SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f48d0fbfdce6c9bd33f85fe698827c708975f37d68de5e4b3e225c3a8bdc87f2' 
  AND token = 'bh2uXsrxu01n8VzqIinCo5I5DlD0FmUrjdrVdWfRH/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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