SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '774ba7ae033431eb4a6f585a9728eabf4dec0a648181cb84b599a65b09d153e5' 
  AND token = 'Kxq97oipBp2UjdPcfXw+5HDzEOd+xYREpJXW85MjYwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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