SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3166b4f156b0acfa59e6b5bffe35a66c981afcacfcd07055c5fcbaf20402a097' 
  AND token = 'ck7sgtaoZLQFahxCWqccQQNlRndXB68pCSAMObjwMnc=' 
  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"
    }
  }
}