SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48be227d642b582381aaa0b08e4f292345b6bd9e9bcfd4bcca892df7d53ed994' 
  AND token = '4LuXVdKLTgbOOf3w+AvK7DmA8H7lUQ4qWCtcejluHnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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