SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '950502075a60c49c717c4e7acba21df81fcc468c54f8ffeb1f9a52988fb81047' 
  AND token = 'YgtjaB4zd8dRj5SFRSWY7e5vXvdyVGmhoTcwQ7UfXTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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