SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c53cc8fb6679751af60748e64d116beca875213d7e539e881ae22c16924d4f0' 
  AND token = 'PuiGaQQtNpA3eXsYMJGSZQ5aSH1P6iuYgpCb5gpNAdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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