SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28ee86f949327ca975ddd7f52885a81773943ad0a186ffe31d0366739b61d00a' 
  AND token = 'mBqZc7V/VH2PLv4+K9D10YSPQHCpdN/iiFftY/wLjo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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