SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c36828f99237851a7a8ba5044fded8ea65b7c982f1f292a59f726c5cc78ea16' 
  AND token = 'IL9jYx/VS+ACXg3NG4CYHaODg021sVVZRuHvnhNFPd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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