SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30aef0231fd42896447b27787232b51bcf4f6b3124d7b2e2436d3ebb1a9deb8' 
  AND token = 'CPKXLlDZvvU61e3kYVEGp5W+7z0fS3PjoHuK+k8/v4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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