SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4f77cb5c578467d6465680b845dc53ab90773de9ea524c980a71bc2ced906f30' 
  AND token = 'iOhsUQfBqWqH6sx6uOOd5Ynpw/7XvTx43lKlRkajIYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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