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 (
    388908, 415510, 388493, 389135, 388528, 
    389332, 388848, 388917, 389012, 388860, 
    389037, 390317, 388549, 389140, 389210, 
    389134, 415627, 390138, 389007, 388587
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "5.87"
    },
    "table": {
      "table_name": "cscart_product_review_prepared_data",
      "access_type": "ALL",
      "possible_keys": [
        "PRIMARY"
      ],
      "rows_examined_per_scan": 19,
      "rows_produced_per_join": 19,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "2.07",
        "eval_cost": "3.80",
        "prefix_cost": "5.87",
        "data_read_per_join": "304"
      },
      "used_columns": [
        "product_id",
        "storefront_id",
        "average_rating",
        "reviews_count"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_review_prepared_data`.`storefront_id` = 0) and (`webmarco`.`cscart_product_review_prepared_data`.`product_id` in (388908,415510,388493,389135,388528,389332,388848,388917,389012,388860,389037,390317,388549,389140,389210,389134,415627,390138,389007,388587)))"
    }
  }
}