SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dcbcafec642da9b3bb5e3049d215adf747cf047bed7dbbbf7a6e1e05da703c3' 
  AND token = 'MTMVDTgFjVNK7wqEIYmZ/7v9RG0NxTMgxiyi9/licxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}