SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0648e151321f8473a1b50a46c4adfe6ff103c6c7179557b5b7d08063cad26b0f' 
  AND token = 'JUJbgA3zouzmWmZLOx3w5cc9UmNJJbjsjqUrmsgfidE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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