SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd5c5416e90f02088450b9707967de2e76988fda03d672b3077f19075e591989' 
  AND token = '1kHlNGTiuV4IssddHduVrPVwwewfqZeK0Mi9E4vzEZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}