SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd185393b98ac631d3c96388f571ea9e8147ae7d892741cb3770bc648db34b427' 
  AND token = 'kNmIMAbUih7HiKqAnp5T89T9AOqZcuoDiHED1wY/4C4=' 
  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