SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd35955048f985f2feba7f4afb7262f3dade6ce5bd99ff9d324c0ee199e11580' 
  AND token = 'BqytjirxMQHBuGNHZKkJKIZjAVn5Shx6+UNyUkTx/34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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