SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b45c1f6dd469677ab911a93c3e7828ffb5a7676d9a756582f0e573cd2780e7d' 
  AND token = 'kqsr+dICf2qgLz/VNqTdRzubB9Tuiw9H0L/2FYUnRrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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