SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32ec72d9e0e0ae88ba0ac5637b0700f4a77d1ed6fa87a258d73a8dd0078aaf53' 
  AND token = '8WjCtsmSrvBhJaaVa5WALUKE2WCEoFQYcgKvYiD0ItE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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