SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4975b7960e8bb09c61cf9838eaa35116d645bf430cf5c7f1382c718cf9cdefea' 
  AND token = 'asdMw7FZTARHw1u+oQkkjIhK4UpDIitlQK/hYGui7Ts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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