I just asked a close friend from Gran Canaria and he replied that no, it is not common, not even in the Canary Islands (where both Lanzarote and Gran Canaria are).
I say "even" becauseIt is true that men local to the islands wouldthere may colloquially address each other as muchacho ("boy"; sometimes pronounced like muyayo), but for a waiter to addressaddressing an old(er) person as chico does not seem to be common.
Also, in my experience, that is unheard of in the rest of Spain too. The usual way for a waiter to address an older customer would be señor / señora, caballero (for male customers), etc.