SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '63debc2ca0d960296735861e4e4d99914a15df6df903b02af4224bf3f06867a9' 
  AND token = 'UrViUQqhb+xTP0Db688HkeOgYkXzYIsw5cvujzcY5/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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