SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cc3308d194f1e23bb1712cfc8fcd1e7ee528c7ac08a08098061e13bcab93602' 
  AND token = 'YSk8PDFmYIiTU6IFv+lcpawmMeBoMMv1VK6sbNlhlW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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