SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '033698fdcc7f4f4d10b134b9d3abcc47f8569d656ce300aee99688724b51451f' 
  AND token = 'jwWCwyFUEHmXh9Hat+tS1UvD7BEtq87IT/9fek/NuDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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