SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0ee860655dba0d1ef233e4f8709e35ea52febbd5ab92f051f610365ae52193f6' 
  AND token = 'B3lMnKcHwTKfDGOv5UIqoYNpcMQqjUUgZj57ikEN3sA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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