SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '625db849e746b803d50d3f3f515945eb9c303c0239664c93bf59bdc2791dfc1a' 
  AND token = 'L0cjrjW0sCSpbYOvNYwFId6SlE+aPB7dqKIg0eCSIgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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