SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f990190fb9b4f7b0e7bac7009ffe0b619fe4c5a223d93dd5366c7fcdc0c5d43' 
  AND token = 'qwivOgAXiKU+l4juZvkVKahqpxrMUH8XShy3ONYkm6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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