SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '271c4c4ab689715aa69cae7939742ff77e51dabcd63cb73c504e369afdf7ab19' 
  AND token = '+CW0bZJVxLpUwursCj+7G3s/Flhg676Ngn2ZDBD9+fE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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