SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58af544f5674c068e28edd1b7b605a323d2169b2b4e6c34371c18780de6f4fff' 
  AND token = '/KgWkHEpCsUWcG7YSyFxxj626/7qmZvm1BsqZGNUnp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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