SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94bff70b4c7efd34275a9cc1a88537436239445b202bff68db8bbcfb49564a76' 
  AND token = 'aA33m3gUVXr0Wkqh4sZe6dqtQ/9IuMVBQGQ21iUZh5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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