SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    720, 724, 721, 722, 725, 723, 761, 729, 
    726, 727, 731, 732
  )

Query time 0.00034

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": 12,
      "filtered": 100,
      "attached_condition": "cscart_products.product_id in (720,724,721,722,725,723,761,729,726,727,731,732)"
    }
  }
}