SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f9e0bf42ffb84fb8d69f683815941ce02a4d359298630eee64a1dc173074056' 
  AND token = 'MjVJGAMFMxjoBu0ywHY3OjS9SyvXCB7M96/I9Ymn+7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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