SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c64bdc7a4d329b3926b44d413c0865a86410d58efa67400c92a5d3b6e59e80ff' 
  AND token = 'rQvxrv8bW/nuRqXvsX73HwWu0qqnlDGw0P8dhFqp+NU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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