A Mac does not have an "Activation Lock" per se. That is an iOS specific lock. However, if your Mac comes back online at any point in time, and you have initiated the Lock command, the Mac will shut down, and cannot be booted again without the Lock Code you set.
I do not know specifically if there is any way to get around the Lost Mode lock. Just remember, everything you read on the internet is not a fact....
If your Mac is lost or stolen - Apple Support
GB