SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25c35bd4b531e312154e850a1f55e9b93f37390819325d8107922a0df96afcc3' 
  AND token = 'Xme2F4IEmGW6PJ3HkTK2N7BP6345Md0q0ltfXlFZZwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}