SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8344828310498aa602f062a16f7a30d3942f5e32b7bbc54b9c2b2e96f6a5b36a' 
  AND token = '1aW7MVHmZWn/QxJOCFDmsYsBLXcuHunLACazjsSs3/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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