SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6f48928980425cd1681961b086df9e597c5f87372bab3b3ae60f33e9257a8dc' 
  AND token = 'XYZJwOTfwX9av7BNv/v3fNuHXFgjwpWy8Yj4cP572+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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