SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad0066fc7e9a35fa111d7d5268624d232078ebe1029a59fb771b5887ea93807a' 
  AND token = 'VGCr/dECQThQgF/Uhly1HYF/EwKqPnXlSiq7n0FTNuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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