SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2ff91414e6b4ee04426501dcbc983d89d73e69c836f4dfe72d444bf3fa468f42' 
  AND token = 'NQbfmisJCDpKUnTqrnBycwwmII3B0PC/NGKc0SMyNlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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