You will need to boot from the live usb and do a repair. The guide @halcek linked is good, just doesn’t cover luks or lvm, which I noticed your using.
First up find out what device and partitions you’ll be working with
Encrypted partitions will need to be unlocked before they can be mounted, I noticed the name is default “cryptroot” from your pic, this is also needed.
cryptsetup open --type luks /dev/ROOT_PARTITION "cryptroot"
Now mount the root partition (for encryption this needs to use the
mount /dev/mapper/cryptroot /mnt
This next step (mounting boot partition) ONLY applies if you use a seperate boot partition
mount /dev/BOOT_PARTITION /mnt/boot
Once everything is mounted you need to chroot into the system
From here you can run an update as @halcek posted, I would also run a couple other commands
pacman -Syu --overwrite /usr/lib\*/p11-kit-trust.so
# rebuild initramfs for all installed kernels
# update grub config -- ONLY if you use grub
grub-mkconfig -o /boot/grub/grub.cfg
Once finished you need to exit the chroot
Lemme know if I was unclear or if you have any issues.