SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a28532980c52b78c4211a1ed904d25737c59947e088af8c1e4c167c55bc9c05' 
  AND token = '2oCXoYw9mlHgBXfEz3bvqQMjoGyCts4tSrjTziyClII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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