SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a612fcf8869c1821daea9c2ad60972fc5e338fc5df3ff3b3b5839c8923ac07a' 
  AND token = 'YAJcxZIWwWBoTH9yQeO/2Ye1sR4HJbzU5m+B7GwkmZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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