SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c1e2687d3de4b74c308082fcea986eae55ab049caf32524200e09777e416799' 
  AND token = 'FD5Ow388ZpRrjySgYj21OQeQgkn4V7gXJYooM05MY2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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