SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc3c3bc6db1cd457d293476eedce1351aec5c01005c90487e39c3ec895a17f39' 
  AND token = 'eLgSeTi33Q/pM3VQabJPn8XPv0Us6YSKpvQ5Cag9D0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables