SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '531f3f3de076aa2757a182c387bd1964a21d4ab0276c87108f0746f9b97327ab' 
  AND token = 'OQUsgyF2tYSD/JIzLZnIolGVLrWvmIaSkfVueV5vtTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

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