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 (
    20125, 20126, 20127, 20128, 20129, 20130, 
    20131, 20132, 20133, 20134, 20135, 
    20136, 20137, 20138, 20139, 20140
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_review_prepared_data",
      "access_type": "ALL",
      "possible_keys": ["PRIMARY"],
      "rows": 5,
      "filtered": 100,
      "attached_condition": "cscart_product_review_prepared_data.storefront_id = 0 and cscart_product_review_prepared_data.product_id in (20125,20126,20127,20128,20129,20130,20131,20132,20133,20134,20135,20136,20137,20138,20139,20140)"
    }
  }
}