SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd24225891385fb61dc07885b35d09dc5707899d072a5a5de645fde12d84e2a8' 
  AND token = 'KXamHMVih8hgILkyMGuJo/EqFifCB0qUmZ7dGWcvkIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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