SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21dbcf3c3155d652de595867d20d4b53982d09d435126797670c26f7955e46a0' 
  AND token = 'YwywsdpUNfmzlfVDrAqP/mgovTGt9ChjByKZ3PIrdBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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