SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '235b9e4811a40e14727c52287b972f9a4e802bc6433520800e75a4625b2215f6' 
  AND token = 'DlOakpHphHZbJ1GEB9PslyKVgokm66QxXZnNjZHdImU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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