The Satanic versions of the Enochian Keys are more or less Satire. Levay himself was not a terribly religious man despite founding the Church of Satan, if I'm not mistaken. He wrote nothing of where they came from, what inspired them, etc. whereas John Dee reports that specific rituals were used over many years to produce the keys that he had developed - attempting to translate what he was told, along side the Book of Enoch (a decidedly less-than-satanic work of theology) from various angels, as acquired within specific rituals.
When reading Levay, you have to read between the lines - if you take it all literally, you're generally doing exactly what he speaks of being against the the teachings of Laveyan Satanism.
As for the "Joy of Satan," ah... well. Meh.