SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86723c6cb9d7362a4a95e5635c8e611486522036259f17207797a24f9b87e72c' 
  AND token = '8UWLBZVZPH0AEHIDggRy8bLbNP/WvnppmvNy2zBsGko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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