SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '192f2b6b195d440635234fd66e2ee66ee976ea2effddaa83ce72bcf78fd1d14f' 
  AND token = 'NASxwmxxmou6XEJcOHqkZ3LoC3jBe+06bHshrixhqRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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