SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '264aae605d1247aa0b31cac2752ec0d09fcca34c7d347911aa4148d143a81a90' 
  AND token = 'DVWzRy3B2XF7pcwwaio+4LHndJZaQjK+Nu3hoZyeJqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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