SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16770fd30bfc97754deb47b5c4a810a8018606052d0613284456042e4b2ffda8' 
  AND token = 'h6HQ8fAQVDLWzF+VutM4JLNO91lG/wU5hd2JjjjDDBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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