SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a076dcd9f4166d26b9d5a82f11063c282fa966b23658b6faa6a350c8408f2279' 
  AND token = 'Dvc+iNt376VTVXX0HnSPkfpC1sRdQHsYKur/nddMHvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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