SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '930dfdbe2cbb69cc511df93223d592b73df1d7d278dd4596d6f3a6c84d478df3' 
  AND token = '1eZhzF6jQtNa8WanJ5IUrDT99uAJnsknlkwjLvXgTyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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