SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c27d917db021c5667fb14379b931c532c1ea5ee7b46dded5ba98381a3de0154e' 
  AND token = 'HI5I77NjLWlULwU8TxTlCKkKzt1OOFqR/jdneSRjWjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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