diff --git a/src/sentry/eventstore/processing/base.py b/src/sentry/eventstore/processing/base.py
index 03f90c65a1303..12459dbb29542 100644
--- a/src/sentry/eventstore/processing/base.py
+++ b/src/sentry/eventstore/processing/base.py
@@ -38,6 +38,9 @@ def exists(self, event: Event) -> bool:
         return self.get(key) is not None
 
     def store(self, event: Event, unprocessed: bool = False) -> str:
+    if not event.get('event_id') or not event.get('project'):
+        logger.error(f\"store method called with event missing 'event_id' or 'project'. Event data: {event}\")
+        return
         with sentry_sdk.start_span(op="eventstore.processing.store"):
             key = cache_key_for_event(event)
             if unprocessed:
diff --git a/src/sentry/utils/cache.py b/src/sentry/utils/cache.py
index 2d7914b4cb9c2..281080ce01a86 100644
--- a/src/sentry/utils/cache.py
+++ b/src/sentry/utils/cache.py
@@ -40,5 +40,9 @@ def __get__(self, obj: Any, type: Any = None) -> T:
         return value
 
 
-def cache_key_for_event(data: Mapping[str, Any]) -> str:
-    return "e:{}:{}".format(data["event_id"], data["project"])
+        def cache_key_for_event(data: Mapping[str, Any]) -> str:
+            event_id = data.get('event_id', 'unknown_event_id')
+            project = data.get('project', 'unknown_project')
+            if event_id == 'unknown_event_id' or project == 'unknown_project':
+                logger.error(f\"cache_key_for_event called with missing data. event_id: {event_id}, project: {project}\")
+            return \"e:{}:{}'.format(event_id, project)