Click on Add new page and choose URL Type: Static
Click button Save - page is saved to the database
Click on:
and instead go to: http://localhost/tomatocms/admin/core/page/list/mytemplate opened me up: http://localhost/tomatocms/admin/core/page/list/default
After I save the layout are created 2 files in: application\templates\mytemplate\layouts:
page.json
page.xml
When removed this page from the list - these files aren't deleted from folder application\templates\mytemplate\layouts