The movie I am looking for was an adventure movie playing in some kind of desert (Egyptian / Texan / maybe even Wild West?) and became more and more surreal/supernatural as the story went on. The movie itself was in color and probably not older than from the 70's. As I said it was a bit surreal and probably also a bit trashy / low budget; maybe a two-part movie, but I'm not sure.
I don't know whether the story played in an historical accurate period, but characters used Revolver pistols as weapons, rode horses for travel, but in one scene an old biplane appeared...
I also don't remember much of the storyline itself, it was probably some kind of treasure hunt / desert mystery stroy. I recall a scene in which a guy on a horse (could've been the villain) was shot at but magically survived unharmed. One of the side characters was a blind man, whose cataracts were displayed by white contact lenses...
The most important part I remember - because I got scared by that scene - was the ending of the movie. Two or so protagonists discovered some sort of temple, which had a couple of statues inside. The characters found a corridor inside the temple that had a bright yellow glow and was somehow otherworldly. They stepped inside it and disappeared. During all this the statues began to 'thaw' (very creepy) and were able to move their eyes, as if they would observe the protagonists entering the light - and that was the ending scene.
I know, unfortunately it's not many details, but I can say that it wasn't "The Mummy" (1999), "From Dusk till Dawn", "El Topo", I checked those out already.
Any hint would be very much appreciated, I've been looking for the movie title for years!