SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14c4551502b577b017277b6e171cced65be660fb60e6c2d9f2a297adfea32032' 
  AND token = 'lIG45XOJs3ZimgU55LzRJH9uLU4sLmWxjDjGNgProCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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