SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '70481c340f736fdb5b28fd1dc1789a99a7961ca850d642ce49a44e42f87ff817' 
  AND token = 'bWN+L1mHZtUvunVmQiE/Px+/OgTxnnTfjgJWqacXHwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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