SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '328046bcf53d693292e5f71637898d2ef3e6e3f051b6ebe705bf658296ee3c91' 
  AND token = 'qztzQYvODsmXVlEZcqBvU/qdO4WAox/myTPTNdx5MBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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