SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82685b5fa21cb82eb97feeecd0490c7a36cd0dbd1fd0658aa88690dc50cb365f' 
  AND token = 'qXZgoO5hRQsZVSMbjZQX3hclYqMAkVhKM5kMFIl0Yw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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