SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d3376d565f9383bb73942d5a22aa09fb67f2c5e5ff524caa4f319b2616ff06f' 
  AND token = 'K7GfBCh/0zvUWZvZQnmkjje1tGDR940Kh6TyAZvU/2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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