SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f8a84adfdc927efa2a5e9faa20bb28cb9f7cd858755a16df08db1f1d9022958' 
  AND token = 'JbRs8QFfttfkTl0XnoBCeHcs7wKxVB1+PUhVfjxbJ7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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