"ain't no passing craze" means "isn't a short-lived fad".
He is saying that 'Hakuna matata' is going to exist for a long time.
"Hakuna matata" is a Swahili phrase; roughly translated, it means "no worries". It is formed by the words hakuna (there is not here) and matata (plural form of problem).
意思为 不是一时的流行或狂热，在Hakuna Matata这首歌里指无忧无虑的生活态度将一直保持。
Hakuna matata 来自非洲东部的斯瓦希里语，大概意思就是 不用担心/没有烦恼，hakuna指”没有“，matata指”问题/烦恼“。
