SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '691e7b2d82ea8007ce9725ec910ce523cb8416269bdedf09657101b84469cdcb' 
  AND token = 'KzbfA0NxytaBrPK+UJ93ViAVHDm+D/1Dr8/zD0RyORA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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