There are simple audio ground loop isolation adapters that are, in principle, nothing other than a simplistic DI box. As opposed to a proper DI box, they have unbalanced connections on either side. This will not give you the common mode rejection of a proper balanced connection, but your separated "ground loops" will then be the two-fold ground connection from adapter to mixer, and from adapter to laptop. Those "loops" are minimal compared to half the room and its wiring (which is what you apparently currently deal with).
Here is an example image:
A proper stereo DI box usually has two 6.3mm TS inputs on the unbalanced side and XLR outputs on the balanced side: you'd use that with the usual adapters/cables, it adds quite more bulk, and the quality is inherently better (due to the symmetric connections) as well as usually done with higher quality components (higher level tolerance, lower distortion, better low frequency transmission). If there is to be a long connection, it should be on the balanced side as that is quite more robust against noise.