SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10075, 10135, 9952, 10074, 10573, 10577, 
    10651, 10642, 12529, 12515, 12525, 
    12532, 12523, 10198, 10557, 10202, 
    10556, 10101, 10558, 10142
  )

Query time 0.00093

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 (10075,10135,9952,10074,10573,10577,10651,10642,12529,12515,12525,12532,12523,10198,10557,10202,10556,10101,10558,10142)"
    }
  }
}