SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a640db9ebd5303f916f9072b4dee4cb1490f5d8f8b4ea3f367a4901c25ba9bec' 
  AND token = 'sIOZaRvKWuaL7stwVmaziWbswZArVwymqFBpO+dxhJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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