表(字符串,字符串)需要索引吗?

在SQL Server 2008 R2上运行的数据库中,我有一个用于全局变量的特殊表:

CREATE TABLE global_variables
(
    name NVARCHAR(50),
    value NVARCHAR(50) NOT NULL
CONSTRAINT PK_global_variables PRIMARY KEY CLUSTERED
(
    name ASC
) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

这样的表需要索引吗 value