At HD, etc, they have 3/4" x 3" x 6 or 8' expansion joints that are tar impregnated fiberboard. After that is inserted/hammered into the gap, a better-appearing sealer can be applied on top.

HD has a self leveling material I've used in the past. It's made by Sikka. You fill in the depth with backer rod and seal the 1/2" deep surface with the compound. It's in the concrete aisle.
Ron

I've used a pavement sealant from Dow Corning for the expansion joints on my driveway and front sidewalk. I really liked it because it installs easily and can handle concrete movements well. It has been holding up great since last summer.

Here is a link that might be useful: Expansion Joints

"I've used a pavement sealant from Dow Corning for the expansion joints on my driveway and front sidewalk. I really liked it because it installs easily and can handle concrete movements well. It has been holding up great since last summer."

Make sure the sealer is rated for the driveway material.

Not all concrete sealers/fillers work with asphalt.
The presence of oil products in the asphalt can interfere with bonding and hardening.

The same is true for asphalt products.
They can contain solvents designed to improve bonding to asphalt that will stain concrete and provide no benefit.