It is possible to deactivate AMP in single pages/posts. For this purpose edit the page/post you want, Better SMP Settings meta box is in sidebar.
Check Disable AMP version and click Update button.
Disabling AMP for a page doesn’t mean that the AMP version of this page will be drop from Google search results immediately. Google has rules for updating caches and this page remains in Google AMP cache till the next update. Read more about Google AMP cache updates in Google developer blog.