SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '799a1e621c5f85819d8f206c5eca60803b8b4951a7d25e31e88aa0e344dc5dc1' 
  AND token = 'icR0EbtqSJBVE9GN1tWVIjFCE7pyE2h/KD/UaixDvFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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