SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cbdec990d029d2817f593ae757e6f0fba1fbe0179993f159c8a21ff07a7f4cc' 
  AND token = 'tXPoRxd4+ZWj3lytxmTDasCZH1oX7vlwgE+qBQke4ck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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