SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28fb896eeb7b41289257dde435743ea2c06d70998481bbe2cc2c2e6a00253f9e' 
  AND token = '7FKlnF/LMJ3ivMrPAtucuB2fnpSV4WQBnDlGMKvGThI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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