Light Transport; Low Wing; 2 Turbojet Eng
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Environment - Non Weather Related; Human Factors; Procedure
We were assigned to cross 35 miles East of ZZZ airport at 10;000 feet. This is a known/common clearance for us. I programmed the restriction into the FMS well in advance of ATC assigning it. We deviated for weather; and were given direct ZZZ after the weather deviation. The programmed altitude restriction would have dropped out of the flight plan when we activated the direct to. Neither one of us noticed. When Center gave us the expected crossing restriction; we both assumed the vertical guidance the airplane was giving us was for the 'programmed' restriction. We flew along fat; dumb; and happy; until Center asked if we were going to make our restriction.  It was obvious we were not and I replied that we were not going to make it. They passed us off to Approach and we expedited our descent. Complete lack of professionalism; and situational awareness on our part. We both agree we are better than this and have no excuse for this kind of mistake. I believe our familiarity with each other as a crew; and the airplane lulled us into a sense of complacency. My suggestion to myself; and my fellow crew member is we need to pull our heads out and do our job to the standards we expect of ourselves; no matter who we're flying with.
On descent into ZZZ airport; Center issued a standard crossing restriction (35 nm from ZZZ at 10;000 feet).  Crew had programmed FMS for expected said clearance earlier in the cruise phase.  During a deviation for weather and return to course (direct to ZZZ1) the expected crossing clearance was removed (dumped) by the FMS as is normal.  Neither crew noticed at the time.  The aircraft was in a descent to lower altitudes as different controllers handed off to the next sector.  The final ZZZ Center issued the 35 nm at 10;000 feet clearance; crew set ZZZZZ to 10;000; confirmed and armed/captured the VNAV guidance.  Crew became aware via visual cues that they probably weren't going to make the crossing restriction about the time ATC queried crew if they would.  Crew informed Center of the mistake.  Center handed [us] off to Approach who issued a turn to the Southeast and lower a altitude.  Approach vectored flight back to the approach course of the Runway XXR.  All other clearances were met and the flight landed normally with no other issues or deviations.Due to the current health situation; company flight activity has dropped significantly.  Resulting in crew losing their 'sharpness' during normal operations.  In addition; the familiarity of the trip; environment and time of day could have lulled the crew into a complacent mindset.  This can easily be addressed with more vigilance and effort on the part of the crew to maintain their sharpness and awareness during operations.  I am personally unhappy with my performance and will insure that this will not occur again.  Through practice; briefing and watchfulness; I will improve myself and help others to do the same.
Flight crew reported entering an expected fix in the FMS before it was issued by ATC but forgot to hit execute; leaving the aircraft high and not making the crossing restriction.