SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eee6358915d001a776102f4f1657d0066fb44548f9ff9b80cee18643cfdb87bd' 
  AND token = 'LPzBL6KcAzuOyc7TVHbRuwm+pBXQHG8HTFS914prWnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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