Hi beesalad,
To ensure that this is not a bug, please check the following areas:
(Quest spoilers ahead)
In the north-east of Felodrift forest, check the bushes near the river's bend.
In the north of Felodrift, check the bushes near the entrance to the Cave of Io
(Quest spoilers end)
If you are unable to obtain the keys from those areas, you may have encountered a bug.
Thank you for your question, and thank you for supporting us!