Neither are good. It's "j'ai hâte de voir le film "Les Miserables" - I can't wait to see the movie Les Miserables. "j'avais hâte de voir... " means "I could not wait to see... but something happened making me change my mind about it". There is no plain past tense with this verbe. Well I suppose you could say " j'ai eu hâte " but that's not a common turn of phrase. In French you are either eager (was and still is) "j'ai hâte" or you're not anymore "j'avais hâte". Nothing really in between. Thing about "hâte" as "eagerness" or "haste". It doesn't conjugate well. If you say " je me suis hâté" it means I hurried up"

In the expression "j'ai hâte" "hâte" is not a verb, it's a noun (la hâte), like envie in j'ai envie de… If you want to use the verb "hâter" you would change the meaning, for example "je me suis hâté de voir se film" = I rushed to see this movie, or j'ai hâté mes pas pour arriver plus vite (I walked quickly to arrive early) If you want to use a verb, you could use something like "Il me tardait de voir les Misérables"…