It seems like you are missing indexes on View_CMS_Tree_Joined.
Does admin work on your site? You may try to go to reporting and run report with SQL (if account in your CMSConnectionString has enough permissions):
SELECT o.name as view_name, i.name as index_name
FROM sysobjects o INNER JOIN sysindexes i ON o.id = i.id
WHERE o.xtype = 'V' and o.name = 'View_CMS_Tree_Joined'
you should have at least 2 default Kentico indexes on your view: