SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c858e322281cfe613787f1baa8877b81aaa32f81ed84b9dc74db2b24075a72af' 
  AND token = 'D7WZ9zR22CJjn5rUWPPFZax6c0Jth+EhpoUkBy2lJR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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