SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cebb6b99550644a08f91b5ced7b833bd189b315aa95638eab6e94aca564eefd' 
  AND token = 'QJ04WeNK3HO0gLl59XKWWHGf5gu3fj2TFLlCmprbq8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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