create table data (ts timestamp(3) time index, val double);

Affected Rows: 0

insert into data values
    (0, 'infinity'::double),
    (1, '-infinity'::double),
    (2, 'nan'::double),
    (3, 'NaN'::double);

Affected Rows: 4

select * from data;

+-------------------------+------+
| ts                      | val  |
+-------------------------+------+
| 1970-01-01T00:00:00     | inf  |
| 1970-01-01T00:00:00.001 | -inf |
| 1970-01-01T00:00:00.002 | NaN  |
| 1970-01-01T00:00:00.003 | NaN  |
+-------------------------+------+

insert into data values (4, 'infinityyyy'::double);

Error: 3001(EngineExecuteQuery), Cast error: Cannot cast string 'infinityyyy' to value of Float64 type

drop table data;

Affected Rows: 0