My first thought was that it was made up. Think the emphasis would be on Em with a short 'a' in the zara, not an 'ah' sound. That way it sounds more traditional. Not wildly keen on it but think it could grow on me. Emily and Zara are both pretty names but maybe a too-safe compromise if you like the unusualness of Emzara.
Don't think it would cause problems. A boy in DC's primary had a very unusual OT name and though lots of the school gate mums raised their brows, the other children loved the name and he was very popular.