SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7db2238be8835635852b75deca583f1bba4bae411fb3541e8ace16bc7c09f3d0' 
  AND token = 'UUwr1cu7sgqMrMTjb6syvt9ih4GWQgNxrzHVwxHFgq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}