SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9492d963c7ab9b2f496ce50bd5437d52bd4a3b98a48326d90915894834d7ed5a' 
  AND token = 'ETu7Dnf8iXxAPb5OfFccWxWIFQK+rlXo04XEuEWxzkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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