No one here knows your 2-year-old better than you do!
It's a loud show with villains, fire, scary music, etc...but a happy ending. Our neighbors took their kids and their 2-year-old was fine but their 6-year-old was scared out of her mind.
IMO, that show isn't scary at all. My kids have been enjoying it since our now 10 year old was 2. I guess every kids is different....but it's a must do for us, we love it.
Our first time seeing it, DD was 5 and DS was 7. Neither were scared and DD is pretty sensitive to dark and scary things (still won't look up in HM). It is loud. We were also with my nieces so that may have helped her to not be scared.
For a 2 year old, it really depends on the child and you would know more than anyone else. You could always just get up and head out any time if needed. Knowing that ahead of time may help as well. Good luck!