SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61d35317678dfc56e704a70634a6151aec6473546c998864d3672bb90d68052d' 
  AND token = 'm3u8fRsJJx/Jk2d0ZPv5JVOPRzUWuQDK/DPQlUDSI8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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