SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f089581b4adf45f8d84b4eae1b028a194c3b88db67761860c0f27849084f57dc' 
  AND token = 'uLiW6vwU3RuJTBVvR6IOwl/GjZSBM9tuaT/e8HKATiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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