SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a602880fe64ad2aa2e3b8fd9ad94bca6e0524148e38acf241fee663c6caae4c0' 
  AND token = 'JY/1cz9MsVeWu/lX5PaX38HFERBtktYhPOXwW3K5wzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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