SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    12513, 9759, 10496, 10560, 10561, 10581, 
    10102, 9940, 10578, 10143, 9947, 10567, 
    10568, 10565, 9933, 12499
  )

Query time 0.00049

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": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (12513,9759,10496,10560,10561,10581,10102,9940,10578,10143,9947,10567,10568,10565,9933,12499)"
    }
  }
}