SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2725cf85cfd0fa28c2070517094be338ebb0356d4971403cdd3c4d4ea6357e0a' 
  AND token = 'EKKSNzSrgF37UlgC9r7gPbdI7csvQzz+Z3ABalERNYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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