SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1519, 1518, 1517, 1516, 1277, 1494, 1507, 
    1499, 1505, 1504, 1503, 1502
  )

Query time 0.00083

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 (1519,1518,1517,1516,1277,1494,1507,1499,1505,1504,1503,1502)"
    }
  }
}