SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7dc8588562eccd6a6a904be2a53e63178043cf07f7b53ee1acf5cdb38f03116' 
  AND token = 'CmKMEzu6+oqCLL2NvqFcVyhYw8EgILDqEFAhEtumt8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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