SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d242bdda410df654b093ab22f41470e7780b6586005c9655a5fceaff0649472' 
  AND token = 'TE416cOugpeo9fGnDphovi2YX/25thcxrSfsVz8egkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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