Well, we all know how to say in Hebrew "moment" - רגע ("rEga"), but "at"? Here we are, facing the eternal question - which preposition is to be used here?* :) Strangely enough, it's - כ-. Yes, כ- is a short form of כמו, meaning "like", "as." When we think of it, we can find something similar in English, too - the phrasing "as for now" also uses "as"!
So, "at the moment" - כרגע. ("ka-rEga")

Example:
At the moment / right now it's hard for me to decide.
כרגע קשה לי להחליט.