SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6edaa31e77d4669322e069c0a369b34764cc669249e1bd68e5675c198c46a856' 
  AND token = '10nnogjFsqDynww6JkkmuoLnHVkjNI1mBR19uWAd/kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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