SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62543995894472d54677907f056d0ae0016fc55d5499365fb31a2ef8493f334c' 
  AND token = 'KlZj7A1PTxmpPng/ew4kH1l8JfckY+7JqtQm9IL1QNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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