SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '690a9dbb3dfc70e3d03999c9559b38b2ce1bf60c7d92c8196fc4afc5a4195c96' 
  AND token = 'I+P0dbi1B9aZvSx7TH9spS3Hqm9CMRdR25qO9LcEMFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}