SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59dfe5fc779db3f2dbf9b89ca82fba9c51b7caea5468683c2cb39e63734e85fd' 
  AND token = 'MKWWsYDBjoGoIbezU4Ol0+PItcBCtwwLFWqAh7Ip/yE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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