SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b0b7123e35b5a43f416ec9ac48891d5c87242753a635c7def1a5a155805d8d7' 
  AND token = 'juYn81zhBrbf2X9+FTterZ9T4Af0uOqO7f30RaPFEuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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