nginx-1.4.0 is the version but there are many servers on which we have installed nginx with version nginx-1.10.2 , giving same error:
below is hexdump output before KEY from those servers on which nginx with version 1.10.2 is running :

00000000 03 00 00 00 00 00 00 00 a8 09 48 58 00 00 00 00 |..........HX....|
00000010 99 ee 47 58 00 00 00 00 50 07 48 58 00 00 00 00 |..GX....P.HX....|
00000020 6d 50 49 e8 00 00 d6 00 65 02 22 22 63 37 32 36 |mPI.....e.""c726|
00000030 64 30 35 38 39 35 37 61 34 62 32 36 62 31 35 62 |d058957a4b26b15b|
00000040 35 32 31 64 31 66 65 64 31 65 36 33 22 00 00 00 |521d1fed1e63"...|
00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000090 0a 4b 45 59 3a 20 68 74 74 70 3a 2f 2f 4c 49 56 |.KEY: http://LIV|

-------------------------------------
actual size of the cache file -
ls -lh /cache/12053/c/71/be411798f851da373230d41a50d5971c
458K Dec 7 18:27 /cache/12053/c/71/be411798f851da373230d41a50d5971c