SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd33968a3b8c1a07032bf28e91b45d9902cd3cb4ab19c8d86de2014d4e899c66' 
  AND token = '6D7zPscG7rhwgbHamBVJ4L/yrR5JRYsA8WQGnQX5MRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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