SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a16653b24f377fc1e92223d8facc92a99dcc29cece20435e64550cac9889139' 
  AND token = '+XZOGghxw+nG9fmFUCuGdG470loxmvbZNEGMzZNOqFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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