SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a70caf1126a30581453b74d1f79d8b3489a8a33782e557803a582d22e88652fb' 
  AND token = 'zHdK2LJKf8Er0QxiPsIJJMUJL5NN7I67XnXNtsfIXHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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