SELECT 
  product_review_id 
FROM 
  cscart_product_reviews 
  LEFT JOIN cscart_users ON cscart_product_reviews.reply_user_id = cscart_users.user_id 
  LEFT JOIN cscart_companies ON cscart_users.company_id = cscart_companies.company_id 
  LEFT JOIN cscart_country_descriptions ON cscart_product_reviews.country_code = cscart_country_descriptions.code 
  AND cscart_country_descriptions.lang_code = 'fr' 
WHERE 
  1 
  AND cscart_product_reviews.product_id IN (400) 
  AND cscart_product_reviews.status = 'A' 
GROUP BY 
  cscart_product_reviews.product_review_id

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_reviews",
      "access_type": "ref",
      "possible_keys": ["idx_product_id"],
      "key": "idx_product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "cscart_product_reviews.product_id <=> 400 and cscart_product_reviews.`status` = 'A'"
    },
    "table": {
      "table_name": "cscart_users",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["user_id"],
      "ref": ["multi_vendor.cscart_product_reviews.reply_user_id"],
      "rows": 1,
      "filtered": 100
    }
  }
}