SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '029ecfb776381b9ff8a5a63888ba7768d4f8642592a183ced4b1162bf11998a7' 
  AND token = 'rSwT6YlSujJlES9J6HF7PMQlfOQcoXW3KZoFxcJ543Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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