SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f93f573ab57ca05e7fde295112205b06347204da232acb302aa70b904c6bdd7d' 
  AND token = 'y2N1tqdQPv3RMyFrl0kCOMshUy5MBxpQBzy3mYLXZfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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