SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.product, descr1.product
  ) as product, 
  companies.company as company_name, 
  products.product_type, 
  products.parent_product_id 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'fr' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
  LEFT JOIN cscart_ult_product_descriptions shared_descr ON shared_descr.product_id = products.product_id 
  AND shared_descr.company_id = 1 
  AND shared_descr.lang_code = 'fr' 
WHERE 
  1 
  AND cscart_categories.category_id IN (476) 
  AND companies.status IN ('A') 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND products.parent_product_id = 0 
GROUP BY 
  products.product_id 
ORDER BY 
  products.timestamp desc, 
  products.product_id ASC 
LIMIT 
  0, 30

Query time 0.00508

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "37.17"
    },
    "ordering_operation": {
      "using_filesort": true,
      "grouping_operation": {
        "using_temporary_table": true,
        "using_filesort": false,
        "nested_loop": [
          {
            "table": {
              "table_name": "companies",
              "access_type": "system",
              "possible_keys": [
                "PRIMARY"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 1,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.20",
                "prefix_cost": "0.00",
                "data_read_per_join": "5K"
              },
              "used_columns": [
                "company_id",
                "status",
                "company"
              ]
            }
          },
          {
            "table": {
              "table_name": "shared_descr",
              "access_type": "system",
              "possible_keys": [
                "PRIMARY",
                "product_id",
                "company_id"
              ],
              "rows_examined_per_scan": 0,
              "rows_produced_per_join": 1,
              "filtered": "0.00",
              "const_row_not_found": true,
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.20",
                "prefix_cost": "0.00",
                "data_read_per_join": "3K"
              },
              "used_columns": [
                "product_id",
                "lang_code",
                "company_id",
                "product"
              ]
            }
          },
          {
            "table": {
              "table_name": "cscart_categories",
              "access_type": "const",
              "possible_keys": [
                "PRIMARY",
                "c_status",
                "p_category_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 1,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.20",
                "prefix_cost": "0.00",
                "data_read_per_join": "2K"
              },
              "used_columns": [
                "category_id",
                "usergroup_ids",
                "status",
                "storefront_id"
              ]
            }
          },
          {
            "table": {
              "table_name": "products_categories",
              "access_type": "ref",
              "possible_keys": [
                "PRIMARY",
                "pt"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "const"
              ],
              "rows_examined_per_scan": 67,
              "rows_produced_per_join": 67,
              "filtered": "100.00",
              "using_index": true,
              "cost_info": {
                "read_cost": "2.65",
                "eval_cost": "13.40",
                "prefix_cost": "16.05",
                "data_read_per_join": "1K"
              },
              "used_columns": [
                "product_id",
                "category_id"
              ]
            }
          },
          {
            "table": {
              "table_name": "products",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "status",
                "idx_parent_product_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "ea201_francemaqu.products_categories.product_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 5,
              "filtered": "8.23",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "1.10",
                "prefix_cost": "29.45",
                "data_read_per_join": "20K"
              },
              "used_columns": [
                "product_id",
                "product_type",
                "status",
                "timestamp",
                "company_id",
                "usergroup_ids",
                "parent_product_id"
              ],
              "attached_condition": "((`ea201_francemaqu`.`products`.`company_id` = '1') and (`ea201_francemaqu`.`products`.`parent_product_id` = 0) and ((`ea201_francemaqu`.`products`.`usergroup_ids` = '') or find_in_set(0,`ea201_francemaqu`.`products`.`usergroup_ids`) or find_in_set(1,`ea201_francemaqu`.`products`.`usergroup_ids`)) and (`ea201_francemaqu`.`products`.`status` = 'A'))"
            }
          },
          {
            "table": {
              "table_name": "descr1",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "product_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id",
                "lang_code"
              ],
              "key_length": "9",
              "ref": [
                "ea201_francemaqu.products_categories.product_id",
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 5,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "1.10",
                "prefix_cost": "30.55",
                "data_read_per_join": "21K"
              },
              "used_columns": [
                "product_id",
                "lang_code",
                "product"
              ]
            }
          },
          {
            "table": {
              "table_name": "prices",
              "access_type": "ref",
              "possible_keys": [
                "membership",
                "product_id",
                "lower_limit",
                "membership_id"
              ],
              "key": "membership",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "ea201_francemaqu.products_categories.product_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 5,
              "filtered": "99.94",
              "using_index": true,
              "cost_info": {
                "read_cost": "5.52",
                "eval_cost": "1.10",
                "prefix_cost": "37.17",
                "data_read_per_join": "132"
              },
              "used_columns": [
                "product_id",
                "lower_limit",
                "usergroup_id"
              ],
              "attached_condition": "((`ea201_francemaqu`.`prices`.`lower_limit` = 1) and (`ea201_francemaqu`.`prices`.`usergroup_id` in (0,0,1)))"
            }
          }
        ]
      }
    }
  }
}

Result

product_id product company_name product_type parent_product_id
9755 Peinture Acrylic 002 vert emeraude brillant France Maquette P 0
9756 Peinture Acrylic 003 vert brunswick brillant France Maquette P 0
9757 Peinture Acrylic 005 gris fonce brillant France Maquette P 0
9758 Peinture Acrylic 009 marron clair brillant France Maquette P 0
9759 Peinture Acrylic 010 marron armee brillant France Maquette P 0
9760 Peinture Acrylic 011 argent France Maquette P 0
9761 Peinture Acrylic 012 cuivre jaune France Maquette P 0
9762 Peinture Acrylic 014 bleu FRANCE brillant France Maquette P 0
9763 Peinture Acrylic 015 bleu brillant France Maquette P 0
9764 Peinture Acrylic 016 or France Maquette P 0
9765 Peinture Acrylic 018 orange France Maquette P 0
9766 Peinture Acrylic 019 rouge vif brillant France Maquette P 0
9767 Peinture Acrylic 020 bordeaux brillant France Maquette P 0
9768 Peinture Acrylic 021 noir brillant France Maquette P 0
9769 Peinture Acrylic 022 blanc brillant France Maquette P 0
9770 Peinture Acrylic 024 jaune entrainement mat France Maquette P 0
9771 Peinture Acrylic 025 bleu mat France Maquette P 0
9772 Peinture Acrylic 027 gris mer mat France Maquette P 0
9773 Peinture Acrylic 029 terre foncee mat France Maquette P 0
9774 Peinture Acrylic 030 vert fonce mat France Maquette P 0
9775 Peinture Acrylic 033 noir mat France Maquette P 0
9776 Peinture Acrylic 034 blanc mat France Maquette P 0
9777 Peinture Acrylique 035 vernis brillant France Maquette P 0
9778 Peinture Acrylic 040 gris pale brillant France Maquette P 0
9779 Peinture Acrylic 041 ivoire brillant France Maquette P 0
9780 Peinture Acrylique 049 vernis mat France Maquette P 0
9781 Peinture Acrylic 052 bleu baltique metallique France Maquette P 0
9782 Peinture Acrylic 053 gris metallique France Maquette P 0
9783 Peinture Acrylic 056 aluminium France Maquette P 0
9784 Peinture Acrylic 060 ecarlate mat France Maquette P 0