SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e71c3e8b651f5ee8b50ab1d24400f77ed2d047b9d0df68ce0fe4930e4764759e' 
  AND token = 'EWOQyd2kFcC1L6AaMEFz/tgG6i5KvYYi0A7/s1PAA4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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