SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99d40c79ead9b013cca0166baf0f8b36a1610b079561fb9252ba30a31ad8ded3' 
  AND token = 'vWZDdlb1NMDogoHn4azPyL0L2psw4Z3Vsngp47GZzEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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