I use Knock on my iMac and think that this is a feature that Apple missed out on with Continuity and Handoff. If your Mac and iPhone can work together and recognize each other, you should be able to use that connection to unlock your Mac.
http://www.knocktounlock.com
https://itunes.apple.com/us/app/knock-unlock-your-mac-without/id692929970?mt=8
http://www.knocktounlock.com
https://itunes.apple.com/us/app/knock-unlock-your-mac-without/id692929970?mt=8