SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb2336be0acbc51f8889382569f5dd8a46dc7ef980924d09afdc11c207c0f5b6' 
  AND token = 'wxnD8JTrN8Ua/mjr/XLi6/oSBKPjhgaTJy+IUuUOQhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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