SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '776e6b52465119dcf989d92075c5bc0df9aac8e46f957db5d07c49f40c43bc7f' 
  AND token = 'RZeeT+9n9OdNnyXGNFNxa6U2LM+u4ED+RqNmBHKuUWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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