SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d98012e957443ae2a7af4d059d6f887639d35e5ebea32588b82178bc36182c' 
  AND token = 'm8bqPMscGfgzS9QfNehevqZa83lzsEV+goq0Gn1O7Hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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