SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '326fb5b2d97f83e549022181496e93de60cd248b58ed1a22dc667d7c1bb14949' 
  AND token = 'pldH2q/h+jKUWRI+qdCiHwgEgT95wmWmvAgbuIZadHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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