SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    808, 1274, 1030, 1437, 1780, 1031, 807, 
    1487, 806, 1033, 505, 395
  )

Query time 0.00115

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (808,1274,1030,1437,1780,1031,807,1487,806,1033,505,395)"
    }
  }
}