SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3b22295abc3d28c5e5721aa16800e86ea84a76948ab0eb1507e3807b9f2f7b3' 
  AND token = 'v+Hi1Mzb8//VqmfKp9aQtDrZScVA+MAwpZRkUYYtIMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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