SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '772694fa04ad6b98cda57561d74fe9c462c9bf40dd227af3aa05309d177ae612' 
  AND token = '/4UoRN2zRXiGExZVKgijV4y/y5fCll3UkKegCEflR2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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