SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63d8635ff3c6019f519822f461f3cbeff9bc009ca8e51f251712f611485bbe51' 
  AND token = '79tzTwpiZvuaasjUwdi26IrLi6x3eAGbTBtnQPi87rY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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