SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b02bd8a9f5129c69f3b9a99086b6a6d9cb9fc9781047b8a7c995b93d354f0d5d' 
  AND token = 'F0mcDvqjxBLFDi5GIwLZlXtLHDpwywNbmFYa+vGrjRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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