SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cff739f17b4150fdc3c4c0834de47c8802246849b0fae3bcea5079b79addeb9' 
  AND token = 'svdzOQyupI7XxL6kHTvNAJm0vC3GzXYmlXwcMMOL8p4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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