Google has silently added a "no buffer" feature in YouTube Video Player - just click anywhere in the red player bar and the video will start to buffer from that position, not from the beginning.
A similar feature already exists in Google Video Player but they even let you bookmark the time / position in the URL itself.
Earlier, if you had to listen to this music video from position 1:33, YouTube would still download the entire clip from the beginning (position 0:00). But in the new version, you can move the YouTube video playhead to any location in the red timeline and the video will begin to stream from that position itself - you no longer have to wait for the entire video clip to load.
Related: Rip Audio from YouTube Music Videos