SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98b80482fbfed7b5ca82937dd29330cd74f9c4cf123c8721516c2f52782ee023' 
  AND token = 'NmLkI8p4xW3hzVeA9v2D6KlBSimqXrR6/QfZpZUN/K4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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