SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58e9868ff1fd4804fde00a12c1236a4bab95f437770738a18fde7be2b284613e' 
  AND token = 'hGTDy7rAjDhPclbmGDYyeeE9I+q6HfyfWKwVoLdHmPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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