SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd09e5d94b3d37f59e200ce14513242fa302de3595db29d8000b1493156b83b56' 
  AND token = 'GxV3ZhKD8N+t2+T1ycbi/3UqZKJTpvKrMUYufwhPuZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}