SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '113b94fbb26d740fe111b239fecf3ca8bbb00590f37799b9b7b99aa14d24abcb' 
  AND token = 'hiwFGuCRRZhVxvGx2hiZuSmLXwLNyq6yxBKHZqk4/Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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