SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e817eb34f49b832390dec3016bc18d58149591669cc1e672f7aa52d76ecf0889' 
  AND token = 'GcdeFaWfYJaxkK9GO3VNUK7vt7YU/8xItAdNG8bXTyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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