SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1618, 1623, 1624, 1395, 1614, 1604, 1801, 
    1802, 1724, 1727, 1726, 1599
  )

Query time 0.00095

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 (1618,1623,1624,1395,1614,1604,1801,1802,1724,1727,1726,1599)"
    }
  }
}