SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3935d45a8ea79ec6de04b6d5be485a5a31f88b80b9df6b385c7ca3f00747b6ee' 
  AND token = 'dWkn0HoZoc8W0CsXpbZlzCN1OZPFD/+JnelqPH+apis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

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