SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e9bdfb0ee751ebf2659d9ab9920fbe176883ee4f874e7e03fa10aac254b2d1f' 
  AND token = 'dddwrSSqlkNFIbHbEdcY9+O7VWyeTL4WRKPHyUkivog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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