SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd4774c796ab8fc1f2dd0f2a6bc7e02d7314988a6bd99e8eea82be2e9467cfec' 
  AND token = '1ct9dMsAth4Qo2MKhO/Xf2ioYcdPCmC7tDlUD45dMnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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