SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b78641eb5257d8755633e7933fb23726a1646cb56702f9d75a5871397f3a047f' 
  AND token = 'LeHbxBwga03GetX+PgpzoYSxgl9U9ZWmHokywZPZPSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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