SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1b7a7d0dbf4fa4ed2521361a84229eca8df7f18a69328f26910d9e66646c70f' 
  AND token = 'XYNf7g9L2zG+IXLl8Z/TNVg5Hd+8VCJY4jzH6TR5lxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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