SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb5954d452ea34dbe527d0b869496a18df8c27a01d2a77510cbbcd55f26c780b' 
  AND token = 'HKhhvzBDkBFRUTEpJCaMBkitMyAh+7rpEB1gZvLcCAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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