diff --git a/internal/cache/keys/keys_test.go b/internal/cache/keys/keys_test.go
new file mode 100644
index 00000000..44fdd59c
--- /dev/null
+++ b/internal/cache/keys/keys_test.go
@@ -0,0 +1,56 @@
+package cachekeys
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/smartcontractkit/chainlink-ccip/pkg/types/ccipocr3"
+)
+
+func TestTokenDecimals(t *testing.T) {
+	testCases := []struct {
+		name        string
+		token       ccipocr3.UnknownEncodedAddress
+		address     string
+		expectedKey string
+	}{
+		{
+			name:        "basic key generation",
+			token:       ccipocr3.UnknownEncodedAddress("0x1234"),
+			address:     "0xabcd",
+			expectedKey: "token-decimals:0x1234:0xabcd",
+		},
+		{
+			name:        "empty token address",
+			token:       ccipocr3.UnknownEncodedAddress(""),
+			address:     "0xabcd",
+			expectedKey: "token-decimals::0xabcd",
+		},
+		{
+			name:        "empty contract address",
+			token:       ccipocr3.UnknownEncodedAddress("0x1234"),
+			address:     "",
+			expectedKey: "token-decimals:0x1234:",
+		},
+		{
+			name:        "both addresses empty",
+			token:       ccipocr3.UnknownEncodedAddress(""),
+			address:     "",
+			expectedKey: "token-decimals::",
+		},
+		{
+			name:        "long addresses",
+			token:       ccipocr3.UnknownEncodedAddress("0x1234567890abcdef1234567890abcdef12345678"),
+			address:     "0xfedcba0987654321fedcba0987654321fedcba09",
+			expectedKey: "token-decimals:0x1234567890abcdef1234567890abcdef12345678:0xfedcba0987654321fedcba0987654321fedcba09",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			key := TokenDecimals(tc.token, tc.address)
+			assert.Equal(t, tc.expectedKey, key)
+		})
+	}
+}