SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f625a6e739301da98aaa58657a4ed08ff8058e47f9653fc4acaec15aee93523f' 
  AND token = '4K1KPmfs1y8DIU7iaLrpWQqlclOlLzRjEys/pbb+ZKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}