SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3220a65495952a2ddf93a936dc87f36bb8d610b57ce31095ac059c87829a30fd' 
  AND token = 'ZlmrMbAshyY//r+244jkQUG5xoXO0g53JFB/vsqqNsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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