SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cd461531eaad985bd4cd57bdd691c6176ac1606f7bf8393fd9cf08792b2493e' 
  AND token = 'MQESayxHdBwx7eyTH8yUEJf1Q2FzmfBJWKSsl/02sJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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