SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a420f0090dd8205d0e0c4c86d4e00c614f6289001d65a6b9e8fdb0be5566a998' 
  AND token = 'Osq71HEQd02yRF9ot5pyhQke7oZtp4fmnUJUKfwX6/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

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