SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70aa1aece602fac2f375321945c7388c89e1a68e6049e8c3ef8bd992c72d8db7' 
  AND token = 'ODzwyIqL8NOAPdGAMQbywhvLLBmcR5QnvN+dQNPuNEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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