I would prefer to say:
1: It's been five years since I've seen that movie.
Guy, your example with such a short time span doesn't work for me.
2: I haven't seen Ali since two minutes ago.
To me, this sounds like
2a: What is wrong with Ali? It's been almost two minutes since I've seen him!
2b: Ali, I asked you a question two seconds ago! Why haven't you answered me yet?
These strike me as abnormal expectations of response times. Instead, I would say:
2a': I saw Ali about two minutes ago.
2b': Relax, it's only been a couple of seconds since I asked the question.