SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef1a99a9146ae09d7925d38a9bfe4b3a0ac421dea5f921895cd99c3fdc0bbd5d' 
  AND token = 'hkaMg1Nw7/btPK4IYbmpeBusSvdZ4Piek0jzDwJS33w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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