SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31808023be6f742fd29dc492316bd731ce57381beed446e65bec1524274aedfd' 
  AND token = 'ofKe2sNJVYn0nJq8k1fKdlILSt0pH4GncGfUr0pG3HU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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