SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8db0b353454d63149b282301e9f21d5287496c9e44308f334b7a92efb3292c31' 
  AND token = 'P/Xwv6OuJgHkfxCBFWd+fvJMVi8LimpsBq/sTp01+zE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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