SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b654c86b2e95c0a8f5e7267c662d84e2380f913cc21753def2686e20bb97209' 
  AND token = '4jgw7pnc0z9bBf8+MLrqseXOrxiVhhMmVzO9xQMHG30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}