SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96893be0d5d61f8668ff40aaef67120805aeab211b07e58f63186d5eb242f206' 
  AND token = 'TpMv1RxYHa+gHt2tX6yhMnk2zoE7YtUZKMsgbWe2jx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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