SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6f2025ccba143cc55bcb052dd7afa2e85acec9f3ab8945b76c8436e53800ac6' 
  AND token = 'FBJ34lET0fDKXLG156cnSn/3GUr1o65G1EV7OD/Glog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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