SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dd361fddbb3551c380a2bb799b3034fb9ccc2e81d160b811598b5a734244f61' 
  AND token = 'GqmwHQB/XhdVEWj8AJUveQfW61wzmX2RdBphXL3objo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00129

JSON explain

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