SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '490bc1047455b7fc8e585ede461bf81b0bf6771571011d77fcff504675898311' 
  AND token = 'lCIzM0nQfx8O1z5eH1litRWl9bfBADe27O36SievRyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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