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 (
    427821, 371897, 371841, 371840, 371903, 
    371852, 371891, 371894, 371850, 371908, 
    371842, 371879, 371847, 371871, 371862, 
    371849, 371846, 371872, 371856, 371901
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00042

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 (427821,371897,371841,371840,371903,371852,371891,371894,371850,371908,371842,371879,371847,371871,371862,371849,371846,371872,371856,371901)))"
    }
  }
}