SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2435adc3b1807e3040aa1b759645a36e5cc133e52e9286e7327ffb14aabfefea' 
  AND token = 'Qo0VeBd+mBZPZApnNwFQCOe+JAEAPS6VXutAdwGsAkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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