SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc69d494a28f8181c921c4fd0c6685d446e8f7f326d138f3b86c16e1c40c95ec' 
  AND token = 'bUYrZ1nWZoKtdXtXXvNEF7yXh6V13Z8iIJN7APgevmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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