SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91cee4248b9732d885660c8d8120f63ac5a55a6fa2f1aee81c9600b5e7dc6c61' 
  AND token = 'i/evzUaog8Dlsj3eY5t+dqC7jV4zqE17nQFM+uHKhSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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