SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10653, 10646, 10645, 10647, 10648, 10649, 
    10726, 10650, 10547, 9789, 10655, 10654, 
    10605, 10604, 9873, 9972, 9973, 9975, 
    9976, 9977
  )

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": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (10653,10646,10645,10647,10648,10649,10726,10650,10547,9789,10655,10654,10605,10604,9873,9972,9973,9975,9976,9977)"
    }
  }
}