SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e15a47ad407a97eba4348b5ba2c42e0914ed1b00b78a8e6cadcd2ccbe19f015' 
  AND token = 'qT49B92kq4/iP7jHIv4tvvU0rfERx/JsFNFEwUwV1LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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