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 (12, 78, 79, 11, 41, 28, 7, 27) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00030

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_review_prepared_data range PRIMARY PRIMARY 7 8 Using index condition

Result

product_id average_rating reviews_count
41 1.00 1
78 4.00 1