SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05d6c1d978c4bc430a3544729cbf5c087740995607ee0723d60ef7006299cd2e' 
  AND token = 'gXHiV2dnPavdiyFp47lPh3gr600xmYqLCOJUTZbfWJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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