SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4b3ed5bbf0fdc79bf59e6a4e7bd88c02bc7db9dfd33749147df1f162818ceee' 
  AND token = 'KjYgOouFN4fj4ZC5kpQWPXnW14M7wfGeOzQdeNpmTEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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