SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52f7405026c172c2cf7cb471e50188f095725ca005aac7430dbc2d454aacdcb1' 
  AND token = '+1nyyWPQZJl8czH+tukt0D9gMhmuCv45nQAjdhA8HPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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