SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    2721, 2202, 2625, 2678, 2824, 2776, 2826, 
    2775, 2777, 2823, 13441, 13762, 11667, 
    11666, 11668, 11665, 13106, 15112, 
    13839, 13838, 13140, 13828, 12505, 
    13829, 13830, 15426, 2567, 2557, 2569, 
    2556
  )

Query time 0.00051

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": 30,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (2721,2202,2625,2678,2824,2776,2826,2775,2777,2823,13441,13762,11667,11666,11668,11665,13106,15112,13839,13838,13140,13828,12505,13829,13830,15426,2567,2557,2569,2556)"
    }
  }
}