SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3654cdd32e6bb66107e8209daac9428034777e5449941b222c675cf62843ce6' 
  AND token = '2UhaJEFH1I0A6QEuXnfoMR7Bl2xqIo+db3LIkLi7mi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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