SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '05ba07c62df7748920f0d3ebbcc64fde2513ab6605e722c1b1fd149591c2ac81' 
  AND token = '6hszYbsqDH6Z7jcum1/3Ftb6gTDKpDs08KgXHsfaVCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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