SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0d89ec4ea809b90c88c5a05015aa238ce7f8b155780225e307277e568d70016' 
  AND token = 'lJZUaleSFoUW7Rpx5Un/BH39gioxrXpX72kP/PY58M8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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