SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02cb3d3ec3311c2e1b19c3a7517f7632dfe0de227219289f06abb9d53eaa645f' 
  AND token = 'n2HoYnu/nk5Vk7Znp5+PH4xk3BXz9vswRz5nm+7VKjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}