Seems like a bit of a non question to me. It would be strange for any language advanced enough to be written, not to have a word for stars. So the first mention is simply the earliest record we have surviving, from the earliest written language we know about. So its probably some sumerian text in terms of surviving written accounts. But in symbolic terms it goes back much further, like maybe 30 000 years ago+ [news.bbc.co.uk]

Even chimps must associate something with the 'lights' they see in the sky at night, which they could surely express in some way - if they could actually talk. What a weird question.