to cause someone to be anxious or excited. The excitement of the moment really keyed me up.Thoughts of their vacation keyed up the children so much they couldn't sleep.
Make intense, excited, or nervous. For example, The excitement of the gallery opening has really keyed her up. This usage alludes to key in the sense of "wind up a spring-driven mechanism such as a clock." [Late 1800s]
To cause someone to be intense, excited, or nervous: The coffee has really keyed me up. Thinking about the party tonight has keyed up the kids. The audience was all keyed up, waiting to find out who won the award.