I just asked a close friend from Gran Canaria and he replied that no, it is not common in the Canary Islands (where both Lanzarote and Gran Canaria are).
It is true that men there may colloquially address each other as muchacho ("boy"; sometimes pronounced like muyayo), but a waiter addressing 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.