SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93ebdf39b73efa1e3d16aa1436853b5583338c7b21f54609222018e97dbee5a9' 
  AND token = 'Vfjl0d3BorCMFFnhF9YXudWVmtEJzTukwVsrpKMqTP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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