SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b730c3709f916d6aff72a3f8c1bada6b7afdd12900d8f45227471df34250df7' 
  AND token = 'qN1Eq9vd2YZxTZXmJGBJKK0g60CYaVzVl0u3Rt/CqTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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