SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82bbede354b90ad0c5fa3fc6c13bf8f279dd7846294de18b302149bb112803ce' 
  AND token = '9NpmVc8+ZCg32EtozSrpEYreF35RtIOVxvTueznKbq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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