SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b4bedd99117bd18c759a4fa29dff394c70b3114a06ce907589b7493c2b328f9a' 
  AND token = 'CQz4yBiDEgN1JnrTRKWolBGKngniHwvWvWXzUCr/x7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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