SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd8b4c61946bdffcb5eb837f0689be1183b1f0cc8fea57d6a3b4fcfd7871c6fa' 
  AND token = 't+GNlWo5tYd/0L/t+DD5GRyLe9zj6W00RxlaHSp8ozg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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