systemctl list-unit-files | grep enabled
systemctl list-unit-files --state=enabled

$ systemctl list-units | grep LSB | grep grub
  grub-common.service    loaded    active exited    LSB: Record successful boot for GRUB

$ systemctl list-unit-files | grep enabled | grep grub || echo 'nothing found'
nothing found

$ systemctl is-enabled grub-common
grub-common.service is not a native service, redirecting to systemd-sysv-install
Executing /lib/systemd/systemd-sysv-install is-enabled grub-common
enabled