SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c81878b44dc8611ed65a5fad652bdbc1c74868036fa27c702b35e91082ac2972' 
  AND token = 'SCq0dn/xVM3ZKN6QQETDe1RgB3gVkNQ6TcolaGBDDKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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