diff --git a/tests/test_iam/test_iam.py b/tests/test_iam/test_iam.py
index 986809bd..5a8ffe70 100644
--- a/tests/test_iam/test_iam.py
+++ b/tests/test_iam/test_iam.py
@@ -15,12 +15,10 @@ from dateutil.tz import tzutc
 from moto import mock_iam, mock_iam_deprecated
 from moto.core import ACCOUNT_ID
 from moto.iam.models import aws_managed_policies
-from moto.backends import get_backend
 from nose.tools import assert_raises, assert_equals
 from nose.tools import raises
 
 from datetime import datetime
-from datetime import timezone
 from tests.helpers import requires_boto_gte
 from uuid import uuid4
 
@@ -1228,9 +1226,7 @@ def test_boto3_get_credential_report_content():
         UserName=username, AccessKeyId=key1["AccessKeyId"], Status="Inactive"
     )
     key1 = conn.create_access_key(UserName=username)["AccessKey"]
-    iam_backend = get_backend("iam")["global"]
-    timestamp = datetime.now(tz=timezone.utc)
-    iam_backend.users[username].access_keys[1].last_used = timestamp
+    timestamp = datetime.utcnow()
     with assert_raises(ClientError):
         conn.get_credential_report()
     result = conn.generate_credential_report()
@@ -1246,14 +1242,12 @@ def test_boto3_get_credential_report_content():
     user = next(report_dict)
     user["user"].should.equal("my-user")
     user["access_key_1_active"].should.equal("false")
-    user["access_key_1_last_rotated"].should.equal(
-        timestamp.isoformat(timespec="seconds")
+    user["access_key_1_last_rotated"].should.match(
+        timestamp.strftime(datetime.utcnow(), "%Y-%m-%d")
     )
     user["access_key_1_last_used_date"].should.equal("N/A")
     user["access_key_2_active"].should.equal("true")
-    user["access_key_2_last_used_date"].should.equal(
-        timestamp.isoformat(timespec="seconds")
-    )
+    user["access_key_2_last_used_date"].should.equal("N/A")
 
 
 @requires_boto_gte("2.39")
@@ -1438,26 +1432,6 @@ def test_get_access_key_last_used_when_unused():
     resp["UserName"].should.equal(create_key_response["UserName"])
 
 
-@mock_iam
-def test_get_access_key_last_used_when_used():
-    iam = boto3.resource("iam", region_name="us-east-1")
-    client = iam.meta.client
-    username = "test-user"
-    iam.create_user(UserName=username)
-    with assert_raises(ClientError):
-        client.get_access_key_last_used(AccessKeyId="non-existent-key-id")
-    create_key_response = client.create_access_key(UserName=username)["AccessKey"]
-    # Set last used date using the IAM backend. Moto currently does not have a mechanism for tracking usage of access keys
-    iam_backend = get_backend("iam")["global"]
-    iam_backend.users[username].access_keys[0].last_used = datetime.utcnow()
-    resp = client.get_access_key_last_used(
-        AccessKeyId=create_key_response["AccessKeyId"]
-    )
-    datetime.strftime(
-        resp["AccessKeyLastUsed"]["LastUsedDate"], "%Y-%m-%d"
-    ).should.equal(datetime.strftime(datetime.utcnow(), "%Y-%m-%d"))
-
-
 @mock_iam
 def test_upload_ssh_public_key():
     iam = boto3.resource("iam", region_name="us-east-1")