SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '823753a5efe08e4ddf0b67222fe691c7ff09930bc14808bfd6431ae1c549fcce' 
  AND token = 'Q+8Lo7qzA+Do0md6s5ctGbdB2gVMpQvvbzoNsZzPTH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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