It’ll expire at its regular time. See this topic which has some discussion about it.
There’s dozens of commodities which have bugged auctions that expired like ~23 hours ago but still show up in the listings, and they can’t be bought out. It’s a graphical bug due to the way the rows get displayed when multiple auctions at the same price are “combined,” the longest expiration time gets displayed for that row. 49710 days is far greater than 48 hours!
It’s due to how Blizzard represents dates in their system and how computers handle numbers. To calculate how long an auction has left (12h, 24h, 48h), the current date is subtracted from the “expiration date” of the auction. Because these stuck auctions expired in the past, that number is negative. But because of how this number is represented, it can’t go below 0, so it just “rolls back around” to the maximum possible value. Which just so happens is somewhere around September 25, 2158. 