I saw this movie in approximately 1994-1995, and a rough synopsis would be that it is about a girl and her companion (maybe male or even perhaps some sort of fictional creature) searching the land for a set of keys in order to unlock a door and free a horse or multiple horses. It was in color, and could possibly have been made for television, but not definitely, as I saw it on a VHS that could have been the real deal or taped from TV. It was a movie that was made for kids. I remember the girl was wearing a dress, and there was some sort of evil force or witch trying to prevent them from freeing the horse or horses.
I never got the name of the movie when I was a kid and only saw it the one time, but it has been on my mind once or twice a year ever since.