If you are desperate for the audio track, the safest and most legal route is to purchase the episode on iTunes/Apple TV, which natively supports the Apple ecosystem and M4A audio formats, ensuring you get a high-quality file without the risks associated with torrent sites.
Searching specifically for suggests you are looking to listen to the episode rather than watch it—perhaps treating it like a podcast or an audiobook. This is a niche way to consume a sitcom, as Young Sheldon relies heavily on visual gags and facial expressions (particularly the exasperated looks of George Sr. and Missy). However, because the show relies heavily on voiceover narration from the adult Sheldon (Jim Parsons), it is actually one of the few sitcoms that translates relatively well to an audio-only format. young sheldon s05e05 m4a