SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33fa30b6815a895f591cf57855cda04f6352c5cb6c97db16aa54f0b289882df7' 
  AND token = 'dYf/CVkiJz/GyESJOWb32GQix02meNjFnItrVqfIvu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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