SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa18d6da8674aa4fd8e50d2af768f60a0a238873d8148c177ad1a233b906847a' 
  AND token = '3lOEyNL7zNXWDuFmR55gdNVqCbuzfrpjHbJgDc4pETc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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