SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd71cb58c7e377e1e8da27762e78e5ebc08031ead44674135cf0af63fc0bba5c5' 
  AND token = 'pkKFml7wzJ+TUKvHBTqBYhoFLeVoDWTb+tgcUGgU/mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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