SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e0395c1bdd94977c14a891090b39453de120c6f522688ac1fd78aaed7cb83ea' 
  AND token = 'JuPn+sjYUioHb1WWh1r3Zb3gbQjKWEyGd/YNILScE+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}