SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a14a43eefec8f34df4419f857c1b660e0ff698fed78af5cd6723e5ed1e77b54' 
  AND token = 'vo+KdofdaPgMGRzIgQ0L+vw/u/d1jXdnBt93YruKtSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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