SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da949d7bb50f79c1af09b285696e22db63b02e509c6b9cde9f539b3d4b2a8046' 
  AND token = '9KlOBOBUY8gzJvXSRWFO1pHZN5xTiilZf3hFmDsskdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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