Actually it's " scanning for Brtfs drives", it looks, but unless you have one, doesn't find.
I've had systemd-fsck hang myself, but, only when it was fixing problems. It may not be fsck at all that's causing your problem. Here's the top of my systemd-analyze blame:
$ systemd-analyze blame
10.506s NetworkManager.service
10.270s ModemManager.service
6.130s systemd-fsck-root.service
5.942s preload.service
5.421s sensord.service
3.448s autofs.service
3.315s bootlogs.service
3.271s loadcpufreq.service
3.172s lightdm.service
2.763s avahi-daemon.service
It's the NetworkManager/ModemManager.service that is increasing my boot time. I can actually see it on the laptop. As soon as the wifi light comes on, the balance of boot time is short. Anyway, just an idea. That is, unless you're seeing error messages after systemd-fsck runs.