Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0b9e2121d1e4d76e7e97b11a21013298ffefbb37a7562cb8bbbe603a9ef52c27' 
  AND token = 'OBfY1CePT5uCoQMuzdlbk+MYoO971jDgEMPIN1Ooj2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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