SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5587e674e975fe91f4210bf8d668b80a279fe496998109b1e20086a8e75273d8' 
  AND token = '9vpqKyY3BlfzLqPAxEBpOcqXwT0WPYT7GoXUIQVGD40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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