Cold air coming through - help

This house was built in 1982 and does not have an HRV system, so I know the air circulation relies on natural leakage through small gaps, as older homes are not completely sealed. However, this is the first year I've noticed a noticeable increase in drafts coming from the window cracks.

The windows appear to be in good condition and don’t seem too old, but they were already here when I moved in five years ago. Would it be okay to seal the cracks to stop the airflow? If so, what would be the best product to use for a basement window?