SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4dfc05cbda0e584afc61a672e9b9f20717ffbd95c4b96d6ceac18732a55cb83' 
  AND token = 'aUi/EMHRyf56JCD4sKReeobBZqsylm3qYGK/Y+hhHOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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