SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20d677a57e75fa36d258370fc11afb48395b9c358bdbdf3d0ac66151d4b4435a' 
  AND token = 'JoGfadGHS2XanR/yfHdnKVEKtfZDmiABC+tXCKCRn2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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