Spark plugs for a Honda Civic Hybrid 2006 with ~ 120K miles

Check your owner’s manual, but I suspect yes. See what is recommended for 120K maintenance service. 120K is the longest interval I have seen recommended for spark plugs so far. Cost varies according to area, so call a couple of independent garages you trust/come recommended by friends and see what they say. West and East Coast tend to have higher labor prices on these services.