Is it normal, that fsck on an SSD takes a second or two? I am on Linux Mint 17.3 and I called
sudo touch /forcefsck
EDIT: ext4 filesystem
There are two kinds of fsck, "normal"
sudo fsck /dev/sdx
sudo fsck -f /dev/sdx
Your computer runs a normal fsck at every boot, which is really fast. fsck -f obviously takes longer, but in newer filesystems (ext4) it's still quite fast. With SSD might as well double that, and your fsck -f shouldn't take long at all.
Warning: Never run those codes on a mounted disk. It can cause severe filesystem corruption.