SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad131d7735ffbfb4993a19c1500364621a8aeefef90695d900c4ce7ed091809' 
  AND token = 'xqBfXciOhIJNrQ8w42Vz6kVkQ3XQ2zXqWunGzB08/DU=' 
  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"
    }
  }
}