if you're willing to learn some Icelandic, here's the list of available jobs:
there's a general application button at the bottom, but you might have problems filling it out if you're not already in Iceland. The first field they require is the Icelandic ID number, which you can't get unless you're already in Iceland (or have lived there before).
the company that operates the airport in Iceland is called Isavia. They also have a website and separate job listings: