SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3ee37c47e8f6a41f14169ec56a28e2fc52010178f11795fd59a22e852a1faeb' 
  AND token = 'YtuHUkviqAzxserD5YXu4GUzPmwFflO57TgDWhsTIio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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