SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45a0c6ae50c74c7ea8518137d71b74f0e40ad3a443ba4bbb6214acd036579939' 
  AND token = '5iyJXBABONe+t4LrdAQdpxjMd6A8INq2d15UzH2braU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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