SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd659fc7d7c0ff8bbb24bf7e486d4e456633ae1c281f0d054af9af2c59106da7e' 
  AND token = 'c5vfs6qMEWJzDKVolpC/F94YVlF7+ZMMLy9Y2nUWS3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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