SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb586c371924d63d7a135b82fdb1cfdf276c4fa364f2b3740d985225ce14969e' 
  AND token = 'ZwHk8/pe/+MPA3TF4u8too+B8VZJiORV5WBjLYISi1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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