SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9b971dc9154609e25302bf0dc055aef7d7c033db3b67e78e6b693808d1e89ba' 
  AND token = 'HcvYkQZsAg5We0IFmM9PBnUVcHPaWrdkPMjnVDy6NZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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