Hi,
I am not aware of any actions having been developed and shared to be used with smartfox or a mysql db.
I don't think that smartfox is the best option for you, have you looked at Photon for example?
and for your db, you'll likely need to create a bridge to a server api ( a simple php set of files and functions) that would give you access to a mysql db. Else it's likely possible to connect directly via a websocket, but then it would mean a lot of scripting within Unity.
bye,
Jean