SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b185bd5a82f128da8cfba3d637aab3258af5fd4d9f3573bc2dfc548360b684a6' 
  AND token = 'laOVRtueJ6MpKiElPzDQRQLpxGRHZxy8sxEQyiWbCO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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