Unlike Chrome, which plays videos inside a heavy sandbox, UC has a built-in video player that supports pop-up play (floating window). You can watch YouTube or embedded MP4 videos while using other apps, without lag.
When searching for the file, ensure the filename resembles the following structure, indicating a generic build compatible with older architectures: uc browser apk for android 422 free
Once installed, you are not done. To maximize performance on legacy hardware, adjust these settings: Technical Paper: Analysis and Deployment of UC Browser
If you truly need a browser for Android 4.2.2, consider these alternatives: APKMirror: This is the most trusted source for old APKs