How long is your keynote?
I am flexible with timing since I customize my presentations for each audience. Generally, one hour of actual speaking including a short Q&A is optimal, but I can also prepare for 30-45 minutes or 75-90 minutes. Additionally, I understand how important it is not to go over the allotted time, and I never do. In fact, I run a countdown timer (the audience cannot see it) just to make sure that my pace is consistent with the allotted time. The presentation will never feel rushed or drawn out, and the attendees will get to their next event on time.