SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37a33dcd2d80fc03a11af5f08c2f7c520618d3193ac5de6cebb300a67bc1560a' 
  AND token = 'wRo1ehx0TypNFV850diKZkREZeuF1qZ36/hw2iVGP7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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