SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25e1c6fc8d7533b2ebb31b3976683c16fcb54a565d01fad53bc378a4cd767ae7' 
  AND token = 'zRjCa++XYhPICzrGvn5LMApl4cBnR23YOBZZWdHza50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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