There are some existing threads on this topic:
Looking for a way to lock a cabinet
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Simple Lock or catch - where to find basic lock - no keypad etc (newby)
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ZWave or Zigbee Controller for Linear Actuators? (Automated A/V Cabinet project)
All of that said, There are hundreds of locking cabinets on the market already. Most of them aren’t smart, but do they really have to be? Get one with a combination and you can share it if desired. Some of them are smart which is a whole other conversation, but I wouldn’t think the cost is justified in a typical home.
It’s true that you can basically use an electric strike method with fail closed, but I wouldn’t trust smartthings to be reliable enough to always open it when I wanted it opened. So I suppose it depends on how much of an inconvenience that would be.
I have friends with family members either on the autism spectrum or with various types of dementia who have added locking cabinets to their homes, but I can’t think of anybody who required automations for them.
But different things work for different people. Yale has a product in development which will be a $79 cabinet lock that works with their august system, but it’s not available yet. Back in January they had announced it for “spring 2020,“ but I don’t know if their supply chain has been affected by the coronavirus or not. It looks like a nice product, though. 
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