SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fae94342108d5fd4a2cd99097995f87b9f5a4e64c9e4081c3b742cea73cfa8f' 
  AND token = 'RIOvU966sJSqff7x7+dgRUYhkYXuGU5yPykBd+QkRy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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