SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b02a3f523f6d91c833e3edb9c2a5904899ea986f8de35f6cadc56ff5b1fea960' 
  AND token = 'kzoph2iSBHxJU0pb+7JJTqTPdUFIoQsAhmVabMbDQ/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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