SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '907a6a8c085d0d66397bbddbd8a93cabc42e3d3daea015d27d31acd7d4a1b45d' 
  AND token = '0EFHbBEhVVKxIiwXGiY/3GjZDivf1wkC1EpLv+LsDIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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