SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7d9fe07eb4bc468ccde8982486ec772179489f34ee280e7708a846b99719525' 
  AND token = 'Ej3L3XtplUUQ5FxNr/idpxZwQ3rp7hZzKWrKf6UC5tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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