SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0961673abc1e8ebbabec88c6bdebb5ef13ea229070c59246f602c2a8a05f7436' 
  AND token = '+7/hLkrUY9AwD7V7yAgQ32GVDv+9GeQj+8+YxoqqrHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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