SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17a3caccbc1bf5e026171f990d04ceb876e0f63dd54e8fdf5554522730928188' 
  AND token = 'Adc3gvVePiAdozz38sO6ki60tuMh4W8RjsCgUpo+7Eo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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