SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaade4a534c638347bac93e219694ef9f8e38027274924c4f57f7bee726d91be' 
  AND token = 'GvxWQ04ge95ibuhJ/7VsD+MajZ26rnZBgivcUvnBhLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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