SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ca7232bb831acf41674a923ea012c5d914abe77264d7f255c5ef0051099def6' 
  AND token = 'oYXg9QpEPNCgHbdOqyhgeMyzZm980eiPxVwBKo5vFuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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