SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    328, 329, 330, 535, 333, 390, 280, 689, 
    281, 283, 641, 309, 691, 693, 559, 645, 
    703, 533, 511, 534, 517, 702, 704, 585
  )

Query time 0.00024

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": 24,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (328,329,330,535,333,390,280,689,281,283,641,309,691,693,559,645,703,533,511,534,517,702,704,585)"
    }
  }
}