SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b88fd9b5939050e848ca6b79e11c870cd77cc366366ca59a6a30e03f129270dd' 
  AND token = 'hzKiIPyfj+CQGkXTazmNMu3FeFYWVlERvXhj3CoMo4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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