Time management during NCSA exam — how fast are you supposed to go?

Did a full timed practice test today and ran out of time with 10 questions left. Definitely have a time management problem.

The (NCSA) National Customer Service Association Certification exam has 137 questions and the time limit is 135 minutes by my understanding. That works out to roughly 56 seconds per question — which should be doable except I keep stopping on "NCSA exam" type questions.

My bad habit: I over-analyze questions I'm unsure about rather than making a best guess and moving on.

Any strategies that worked for you? Specifically:
- Do you go through once and skip hard questions to come back to?
- How many questions on "NCSA" should I expect — is it worth the time investment?
- Is the real exam usually easier to pace than practice tests, or harder?

I'm good enough on the content, I think — it's purely pacing that's failing me.