SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2e861418fd3f28594d292af97ab446b4b63fa4e99c5220d88b34b21e15926c0' 
  AND token = 'jdJ0bGblNyXFikM80KXCSuDvyqTVKrPYtcaxtk87EOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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