Got a recruiter inquiry today and declined it thus:
Hi $RECRUITER, thank you for reaching out, but I am not interested at this time. I'm happy in my role at $JOB.
Also — I was approached by $COMPANY on my last job search, and spoke to them about a possible role. After the first call I was definitely interested and we agreed to move forward, but after submitting my availability for the next-round call, I never heard anything more from $COMPANY.