SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '388f86d1de244f363cc86f04cae44d907121c661a2de7314de3ba73656cc1c3c' 
  AND token = 'ShyU0ocjeydjLkv2RlClpMGHeWbnhKAJa67HIJh3gJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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