SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e3bdf4ad8f53dd5514aee5a639e8ebef6e7c7814accf76fe25fee5884b50a6c' 
  AND token = 'GBeUA0+damKg9lvP6teQGhA2DwDtYYq6bPhWT3/gvJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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