SELECT 
  cscart_product_review_prepared_data.product_id AS product_id, 
  cscart_product_review_prepared_data.average_rating AS average_rating, 
  cscart_product_review_prepared_data.reviews_count AS reviews_count 
FROM 
  cscart_product_review_prepared_data 
WHERE 
  cscart_product_review_prepared_data.product_id IN (
    329, 330, 331, 333, 334, 335, 337, 338, 
    339, 341, 342, 343, 371, 372, 373, 374, 
    375, 376, 377, 378
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "16.63"
    },
    "table": {
      "table_name": "cscart_product_review_prepared_data",
      "access_type": "ALL",
      "possible_keys": [
        "PRIMARY"
      ],
      "rows_examined_per_scan": 72,
      "rows_produced_per_join": 19,
      "filtered": "27.78",
      "cost_info": {
        "read_cost": "12.63",
        "eval_cost": "4.00",
        "prefix_cost": "16.63",
        "data_read_per_join": "319"
      },
      "used_columns": [
        "product_id",
        "storefront_id",
        "average_rating",
        "reviews_count"
      ],
      "attached_condition": "((`pankajecarter_systemfour`.`cscart_product_review_prepared_data`.`storefront_id` = 0) and (`pankajecarter_systemfour`.`cscart_product_review_prepared_data`.`product_id` in (329,330,331,333,334,335,337,338,339,341,342,343,371,372,373,374,375,376,377,378)))"
    }
  }
}