SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84bd007d73181782f792c501d9b4b50bb7d00026684a3a98fa497e3775bc9405' 
  AND token = 'VfYLf5kV5F6oMvqhgStUFum4aV/xAc8WxR264gibmHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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