SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '706229835206129d340e95f6442d2d1790ab9b28714baf97b1bc3ec24132ce11' 
  AND token = 'lIWiXeO7Ti4m8KfcZ08vafdlEmESny7VfC6TpC+uUgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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