This meme originated on twitch, primarily from Dyrus' stream. One day during his stream, the playlist got stuck on Sandstorm and the song just looped continuously for whatever ridiculous period of time he streamed League for (back then his typical stream was anywhere from 8-12 hours long). At the time, Dyrus was one of the most popular League streamers (and still is), and answering Darude - Sandstorm to questions spread from there.
It's been a popular thing on League streams for longer than it's been generally spread.
My guess as to why the specific origin of the meme isn't on KYM is because that stream was a long time ago, before Dyrus (or most other popular streamers) started making vods of their regular streams. It was also streamed on own3d, which has since died, so not even the records of the stream time exist.
