SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '674a663b33ab3652dccc669e62821cd677d04bde5a81c0822947028c21bef115' 
  AND token = 'BnZQuCKze3Hy8KB/0+GMlNXzRwVU5k47db9vzfxTov8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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