Since upgrading to High-Sierra "lock" takes 5-10 seconds to lock the screen.
I'm sure this wasn't the case prior to the upgrade.
Here is a super simple workflow which uses keyword ('simlock' by default) and simulates ctrl-cmd-q.
---- LINK REMOVED ---
Note: this is now fixed in 3.6 b893 pre-release, so workflow is no longer needed
Note @Tetsugaku you'll need the Powerpack for this - if you already have this, could you please fill in your registered PP address in the forum profile, this is only visible to admins.