SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbc9c2cfdfe790c63ee4fed566a4abb4b003afbecd79ff38e374ea5dc4201add' 
  AND token = 'sgKRWWoxuPxxECN3JQEfHcLDX6gOfX8gJMgT+Vovh1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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