Yup. Use any lens from any era that you want. It will all mount and function. Just be aware of whether the lenses you put on this k1000 are full frame or not.
Let me explain: All lenses project the image onto the back of the camera, where the image is recorded. But some lenses project a bigger size of image than others. Film lenses (aka Full frame lenses) make a bigger image while digital lenses (Aka cropped lenses)make a smaller picture. If you put a made-for-digital lens on your k1000, you'll notice that all of your pictures will be black around the edges, like your were shooting through a pipe or something.
Only some modern Kmount lenses are full frame, like the 50mm. I don't know about any others, honestly.
You're best just buying vintage manual lenses for it anyway because that body can't autofocus a modern lens anyway.