SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54078b39f37d6d758d183e11541cb56dd96a2092db5b2e20c52d355957c5ba24' 
  AND token = 'xkC5GF6aELJ9cyty+e1UjrzdWFJUhBapiFpituMwARU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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