SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '263e3bf32ea82664c705562766f941e8742a794e7dc037ac433aa3b9069ca476' 
  AND token = 'HMPahd+SJ6feoamaIjwhA9yc+/+QIQek7Xd56/hShmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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