SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe7762eb0ab59421007582b2ab6f61028535b4495a559e6fc181286dfc621881' 
  AND token = 'pbzmeqbY/xSGghHmuT53vYlxs36x8ODVTRuIhGzvaxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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