SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '869949b8a6c4941399dfb456211d1a772fd3eab580284de4785ef5b15cd5613f' 
  AND token = 'IgmVuk2cLNgU5BOT9q/WqV63vK+PJU3hEB55VsB0G28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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