Hi, I get to work with 3 to 4 year old scores almost every year. A lot of people sit on a GMAT score for a year or two before starting the applications. I have worked with many applicants who had applied in the last two consecutive cycles without any success, and they came to me in the third year.
Last year, I met someone I would call LAZY- I liked that that applicant and he was great to work with, but I had never met anyone with a 4.5 year old GMAT 770. He did not do round 2 for any school as his score was valid till December last year. He had a great application year with multiple admits and decent scholarships from US Top 10, 20 Ranked schools. ( Check this
https://pythagurus.in/success-stories/ )
I would not recommend anyone to sit on a score for 4.5 years. However, if you think you will have serious time constraints later, take it now.