SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c59ab893052a500dc3175c09de727c383ccb6477ddf501d4f5ff7f4ba8ddd73f' 
  AND token = 'WElZhyuMpk1hJW2XIjpXHY8/tvHFMQS5YjqyoxgqrSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00073

JSON explain

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