SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2b61fd3499ae6dfc00696b85c42185326e17594220c345d12d3889a959c0391f' 
  AND token = 'ny3r4awU57E/HByduOev+7mlVuoWI9PGDXA5R9lXODU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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