SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0e29e8a3ebf1dde509fe1939bbb7b4ccd02976468d55c24e94631f3f9d3d1a54' 
  AND token = '8XbfXzzmsB9HqMazx5ERKChkNsrbeCPW167OlUX5WmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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