SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43ffbfe987c39119382ddb911aea590c6fc81425c69c25f1c5517e9013b884e3' 
  AND token = 'BI2MrN/olFXWIgubTcguxGatmmKgV2bFMkunQl11KbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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