Open the Macro Manager administration and search for macros which should be deactivated for all user except administrators.
You can switch from tile view to list view and filter all macros based on their title.
Deactivated macros will not be visible within the macro browser or available by using the keyboard shortcut "{".
Please note, that already inserted macros won't be deleted and Copying those macros will still be possible.
If you don't want your administrators to use those macros either, you can activate the option "Restrictions for administrators".