SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10511, 10510, 10509, 10508, 10507, 10506, 
    10505, 10504, 10503, 10502, 10501, 
    10500, 10499, 10498, 10497, 9839, 12702, 
    9841, 9848, 9840
  )

Query time 0.00064

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 (10511,10510,10509,10508,10507,10506,10505,10504,10503,10502,10501,10500,10499,10498,10497,9839,12702,9841,9848,9840)"
    }
  }
}