SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48b15cf0800a3cb3d85f2dd3bcf6cd54cf6c9e4e88f8d758eabe24f935342cf8' 
  AND token = 'goqKnyOwqlnejSz0CwIvsTiT2TcTkSFqtzTKY7R1hAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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