SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '202bbde9489079bcdb3d01a1f6de8263c967641d5b5110132fb286d7c34671a9' 
  AND token = '5SogrKBQt8FOjVsqJX1rFEQO2+2DmqKgiB+1NHpTymI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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