SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24cf17f8160223ccf531f4f025bedd5b6692a79eb4982c1edc93a7d07aca5d5c' 
  AND token = 'oURAdN+COAiEwg0BLkvOdfw8SrLWzS+pZvPNV3+szEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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