SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58c767497d9bbb90f49bab3b7cf8dbe801131c0185ffa5c8fa44a6493bff5be9' 
  AND token = 'ijsDt8Wp4641zyC+lp9hNQo1C68bBw4ZWwQBaxzn7Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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