SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  descr1.product as product, 
  companies.company as company_name, 
  variation_group_products.group_id AS variation_group_id, 
  products.product_type, 
  products.parent_product_id, 
  cscart_product_review_prepared_data.average_rating average_rating, 
  cscart_product_review_prepared_data.reviews_count product_reviews_count 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'ja' 
  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') 
  INNER JOIN cscart_product_variation_group_products AS variation_group_products ON variation_group_products.product_id = products.product_id 
  LEFT JOIN cscart_product_review_prepared_data ON cscart_product_review_prepared_data.product_id = products.product_id 
  AND cscart_product_review_prepared_data.storefront_id = 0 
WHERE 
  1 
  AND companies.status = '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 variation_group_products.group_id IN (10) 
GROUP BY 
  products.product_id 
ORDER BY 
  NULL asc

Query time 0.00005

JSON explain

{
  "query_block": {
    "select_id": 1,
    "temporary_table": {
      "table": {
        "table_name": "variation_group_products",
        "access_type": "index",
        "possible_keys": ["PRIMARY", "idx_group_id"],
        "key": "PRIMARY",
        "key_length": "6",
        "used_key_parts": ["product_id", "group_id"],
        "rows": 7,
        "filtered": 100,
        "attached_condition": "variation_group_products.group_id = 10",
        "using_index": true
      },
      "table": {
        "table_name": "products",
        "access_type": "eq_ref",
        "possible_keys": ["PRIMARY", "status"],
        "key": "PRIMARY",
        "key_length": "3",
        "used_key_parts": ["product_id"],
        "ref": ["smscrm_edev.variation_group_products.product_id"],
        "rows": 1,
        "filtered": 99.19028473,
        "attached_condition": "(products.usergroup_ids = '' or find_in_set(0,products.usergroup_ids) or find_in_set(1,products.usergroup_ids)) and products.`status` = 'A'"
      },
      "table": {
        "table_name": "cscart_product_review_prepared_data",
        "access_type": "eq_ref",
        "possible_keys": ["PRIMARY"],
        "key": "PRIMARY",
        "key_length": "7",
        "used_key_parts": ["product_id", "storefront_id"],
        "ref": ["smscrm_edev.variation_group_products.product_id", "const"],
        "rows": 1,
        "filtered": 100
      },
      "table": {
        "table_name": "descr1",
        "access_type": "eq_ref",
        "possible_keys": ["PRIMARY", "product_id"],
        "key": "PRIMARY",
        "key_length": "9",
        "used_key_parts": ["product_id", "lang_code"],
        "ref": ["smscrm_edev.variation_group_products.product_id", "const"],
        "rows": 1,
        "filtered": 100,
        "attached_condition": "trigcond(descr1.lang_code = 'ja')"
      },
      "block-nl-join": {
        "table": {
          "table_name": "companies",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY"],
          "rows": 3,
          "filtered": 100,
          "attached_condition": "companies.`status` = 'A'"
        },
        "buffer_type": "flat",
        "buffer_size": "17Kb",
        "join_type": "BNL",
        "attached_condition": "companies.company_id = products.company_id"
      },
      "table": {
        "table_name": "products_categories",
        "access_type": "ref",
        "possible_keys": ["PRIMARY", "pt"],
        "key": "pt",
        "key_length": "3",
        "used_key_parts": ["product_id"],
        "ref": ["smscrm_edev.variation_group_products.product_id"],
        "rows": 11,
        "filtered": 100
      },
      "table": {
        "table_name": "cscart_categories",
        "access_type": "eq_ref",
        "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
        "key": "PRIMARY",
        "key_length": "3",
        "used_key_parts": ["category_id"],
        "ref": ["smscrm_edev.products_categories.category_id"],
        "rows": 1,
        "filtered": 100,
        "attached_condition": "(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')"
      }
    }
  }
}