SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbf5f5493166439539608705ff0c26cea3716756574c9012b7fb43a960d99da1' 
  AND token = 'XvBNl0NdAjV09UMb//nLnHDsbIBcTauivNmMw0AGFGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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