Catalog API - catalog/search not retrieving item with sku

I had an issue with this as well.

I found that the fix was to select ITEM_VARIATION in object_types

So I ended up with

{
    "begin_time": "2021-21-06T12:00:00Z",
    "query": {
      "exact_query": {
        "attribute_name": "sku",
        "attribute_value": "MYBARCODE"
      }
    },
    "object_types": [
      "ITEM_VARIATION"
    ]
  }

Hope this helps!