SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73d2757079caf2d26c848267615e39183d5d1f50824688e831bf108ae74d99f1' 
  AND token = 'bMqsdWepVu3lgiFZFu7ZzwyuU9ahAvQ6z5M247rZzsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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