Fast, no, but you can use dungeonbuddy to farm heroics/ normal for some AP. Also BGs are a good source (but risky).
There is 2 good AFK ways now - Clear all WQs, not only AP ones, but all, so the new ones pop sooner, with bigger chance for new AP WQs Or try to suspend clearing the majority of Suramar quests until you stack nice AK levels, like 22-25.