SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e45ca89eedbad00cd66a90ab646f5021de0715bde50e535d70eacc59fa7a72c' 
  AND token = 'BGQAbo4M5H4bBe31kEgM8bUnDZKpx8GewEbMdg0t0S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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