Shaco can gank lane at level 3, but other Jungles can only do it at level 2. Is it OP? You might think so, but consider the following ways to prevent this from happening:
1) invade him and ruin his box set-up, you know where they will be
2) ward the enemy tri-bush after your Jungle finished blue
3) play back and don't push your lane out unless your Jungle is coming to help (they will have smite up so they can take Shaco box out of the fight and Shaco still can't beat most bruisers 1v1)
4) Pick a lane with mobility or reliable hard CC (why wouldn't you in the first place?)
You could also just ban him as well (please don't, I want to play my main) but there's no reason to since he isn't any stronger than a champion like Rengar or Kayn which will be picked instead.
In essence: Play smarter, not harder.