SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0efdd81638a29ae9934973008a9cb458dd0fc91d11cfa20fe0382004099059be' 
  AND token = 'yH0BNB0+bmLrMXe83Tgs2X08d/IkvIrNub3EXziCAFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}