SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bcc5c104c7c5686667526214be347b29bd552eb66f97db45ea99ad33bae8fc5' 
  AND token = 'X4B1mwVvr+J4N/sOjDQCqOQFqGWvWiwnzkRG319ZflA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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