SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a6da90ab4a011d6fd9cb078cfe52f83e303faacb0d6ac8df3238b0a384f8514' 
  AND token = 'mngDKUTg2nGJAzbgKTazy+B8qrkME8ER4X6n456RvjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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