This is a query to find all the indexes in your table including when it was last updated

Find all indexes on all tables

SELECT
	OBJECT_NAME(OBJECT_ID) AS 'Table Name',
	[name] as 'Statistic',
	STATS_DATE(object_id, index_id) AS 'Last Updated Statistics Date'
FROM
	sys.indexes
ORDER BY
	 STATS_DATE(object_id, index_id)
DESC

Find all indexes on a particular table

SELECT
	OBJECT_NAME(OBJECT_ID) AS 'Table Name',
	[name] as 'Statistic',
	STATS_DATE(object_id, index_id) AS 'Last Updated Statistics Date'
FROM
	sys.indexes
WHERE
        OBJECT_NAME(OBJECT_ID)  = 'YourTableName'

This SQL query returning the information about number of rows in the table as well as number of update/insert/delete after the last index has been rebuilt

SELECT
	'TABLE ' = substring(sysobjects.name,1,30) , ' INDEX ' = substring(sysindexes.name,1,30)
	,sysIndexes.rowcnt, sysindexes.rowmodctr
	,[last updated]=STATS_DATE(sysobjects.id, sysindexes.indid)
        ,user_seeks,user_scans,user_lookups,user_updates
FROM	sysobjects
INNER JOIN sysindexes ON sysobjects.id = sysindexes.id  AND sysindexes.indid > 0
INNER JOIN sys.dm_db_index_usage_stats iusage ON iusage.object_id = sysobjects.id  AND iusage.index_id = sysindexes.indid
WHERE
	sysobjects.xtype = 'U'
AND
	iusage.database_id = (SELECT dbid FROM master.dbo.sysdatabases WHERE [name] = db_name())
ORDER BY sysobjects.name