SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ab0282f6419b40e83df293263a293b0ca24a905e06da6afb124e9600e419ba8b' 
  AND token = 'ulf97oHxH8ePD0rPdwSeGMHeNTcXwR71eS4cL70ogrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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