SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61b96c67675e98027a13953ef456b2c10579f67345038b21dd45e69dfd011e21' 
  AND token = 'RxYSZreGvLcEwlHtZS/lX3FHXgU3BSDKDMVfGHQgBcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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