SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2ed8558401c5235b992ff05528235b07a2e2c6c87479393bcc60184cbfda4798' 
  AND token = 'eL62VV5SnHKb8RvJiRq1EpXYWvVywOf6qRMU8iQQUYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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