SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10504, 10503, 10502, 10501, 10500, 10499, 
    10498, 10497, 12592, 12591, 12590, 
    12588, 13091, 12623, 12587, 12585, 
    12595, 12593, 12620, 12619
  )

Query time 0.00063

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": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (10504,10503,10502,10501,10500,10499,10498,10497,12592,12591,12590,12588,13091,12623,12587,12585,12595,12593,12620,12619)"
    }
  }
}