DECLARE @index_name NVARCHAR(MAX), @table_name NVARCHAR(MAX)
SET @table_name = 'agendatelefone'

SELECT TOP 1 @index_name = ind.name FROM sys.indexes ind INNER JOIN sys.index_columns ic ON  ind.object_id = ic.object_id and ind.index_id = ic.index_id INNER JOIN sys.columns col ON ic.object_id = col.object_id and ic.column_id = col.column_id INNER JOIN sys.tables t ON ind.object_id = t.object_id WHERE ind.is_primary_key = 0 AND ind.is_unique = 0 AND ind.is_unique_constraint = 0 AND t.is_ms_shipped = 0 AND col.name = 'ddd'  AND t.name = @table_name

DECLARE @sql NVARCHAR(MAX) = N'DROP INDEX dbo.' + @table_name + '.' + @index_name

IF @index_name IS NOT NULL
    exec sp_executesql @sql