The section newmtl in the mtl file can contain a line starting with "map_Kd " followed by a path and file name to a texture image file. Usually there is no path and just a filename which indicate the texture images should be in the same folder as the obj and mtl file.
Possible cause for not seeing a texture: the referenced texture image doesn't exist, is named differently, has an invalid image format, or has a wrong path.

This was the solution! I managed to get the basic texture now loaded onto the model I was trying to import, thank you!

Now just out of curiosity, the model I downloaded included 4 different texture files: a basic one (which is what I used), but also included a "cavity", "normals", and "occlusion" version. I assume these remaining 3 files are for other purposes and not for use here?