SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1f450c581219d47c592c34145b70a60700174ca289e87e09e26c74ee34d349d4' 
  AND token = '000BhJAHlIlLFKFQyJS2ohKmZdRM9SYIMTAXRD6Kqzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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