SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39bc2511df5a463dace6b4f6a7a3d1f4ed8ce893b69bcaa2e59b2ef7ba4c089e' 
  AND token = 'msjjzSY3P0dD96VTZmPy7yvTCcCzL8UMU33L+Uy9DNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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