SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd27e1cfad4a3e5d3713dbb70f7d4d18101f253e64cc98f804d012cdae303c74f' 
  AND token = '4QR6xT1Z8hIp0nAYBT29nGIPmiXP1hGJNjvF6p9ulOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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