Based on the facts provided the statute of limitations in Nevada is 6 years (NRS 11.190). Pursuant to JCRCP 16(1)(a), you were required to have a document exchange within 30 days of you filing the answer. At some point, the Court is either going to set a status check or set a hearing date or dismiss the case. I would not suggest filing a motion for want of prosecution. You may want to consult with an attorney who could review the court docket and advise you how to proceed.
While I agree with Attorney's Andrew's answer, however, you can still file motion to dismiss, or expedite. Again, filing affirmative defenses does not mean that you have a meritorious defense by itself. The plaintiffs should have contemplated discovery during this time period. In actuality, they file bundles of such cases, with the expectation that they would get lots of default judgment. They are shocked when someone oppose their lawsuit. Also, this cause them more of attorneys fees.
Only see a licensed attorney before you make any decision. This answer may not be perfect in any given situation. However, more fact may be required by your local attorney.