SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e79e863494a8545d4f9d33aaa83c5aee07b2bd192fdcd9767bc153067fd4412' 
  AND token = '+CAUU96hdqc3u6FRStIxW3i5MtgRDQrVqA9mUNhCtmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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