SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7d94455b6a871812c11e8799733e4cd6641760d564815b1221779652e03fc6c0' 
  AND token = '5++fj3ME8K+v5RQczJaxpvNj51hChROLecglGuLRbNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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