SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cf7481742375c60903aa9b8911a81445a6652896157cfe694144fb9abdbfdf5' 
  AND token = 'efa7uggZXdcT0t8H+CIFsuEY4yEe3zddt6I9Ows9UK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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