SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d70073790f75d44d0a03f33581066c1aaa4e968e502bff50cf00df52b7ef04b' 
  AND token = '4PcBa5/k2c5pzPvFQTEeWpHKfIoFu2iI0NXUsMywqx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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