SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b6a9dd61eb9954de64b554e42779a8754a00e7fb138ca8d6d38f030a15b1b17' 
  AND token = 'SJWlR4FSgIzLJgktKVYwKFqWGjTra2W/vEYrhBO64So=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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