SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '604ce42a9d12fa2c1a35220f5bbaeb0e18a8cb7141ace1ee25ea3de502f6ed8c' 
  AND token = 'Kdn4rpHoF/a4trlmwIx8d0TCOiZLzVokDeU8B3BbzX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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