I have used the locate command for many years and like the fast response time that updatedb gives.
Now I'm switching over to using a GUI (Krusader has a GUI for it) and need to search two or more terms, that need to be all found (AND condition). How can I do this with the locate command itself, without using grep or something additional?

Is this possible via Regex?

I'm a little amazed that any search tool would not support AND OR selection, as it becomes pretty much useless, considering that we now have millions of files and search for just one term returns an uselessly huge amount of results. I do know that updatedb is ancient, so maybe it is just too old to handle requirements of the 21. century.

Is there an alternative to updatedb, maybe one that actually knows when files change, instead of having to scan the whole filesystem from scratch every time?
It should be something that is CLI based (but of course also with a GUI / frontend for easy access).

From the GNU findutils manual:

Too bad, the GUI of course doesn't support this very important option:

https://docs.kde.org/trunk5/en/extra...er/locate.html

Do you know another GUI or frontend that uses locate and gives all the options?

Knock up a script, pop a dialog box with zenity or whatever and show the results.
Simple.