SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19783f958054a39cf56f7be20775f9c79d4f7bea73d9b056b33bc6f0dcacf3c3' 
  AND token = 'KNTPd/nq0YgF1uGmLWQKPmD/peEawK+V9rCkpYel7UY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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