Are you sure? They are created by the installation wizard when the other fields arte created, I dont see how the other settings could be saved, but the admin user an passord not be saved
If you are using PHPMyAdmin, you will need to manually go to the past page of records to the admin_username and admin_password. they are created as the last records with an ID of 73 and 74. I use Sequel Pro, but here is a screen shot those records in my table.