SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ddeccca5bcc3531ab121d46c757f737f5b136f0affffda880902482180cb973' 
  AND token = 'mQRpdgxp7s8ZGTw8YzXpjA7Zw1QM0OI3qxsxUK1Gug8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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