SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b8c9ea5e4d5df67bcbdd7b370f4e52dc0cce0b5dfd9a51126cfe7922c2fe04f' 
  AND token = 'I6W0XjHfEx2GzYvWEzUW78XLrPOh5vpigWwnPiy7HG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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