SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0ec93afb9c79746ef961b6633bcc95a82e7b7fdb741c7ba32743f26593bbb4f' 
  AND token = 'XhKNEgZHY32me/x0QUFBoCxXiWUeGgEyI0nCjgVErEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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