SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9c2fda4b3a64bc5a541b86c7e4ee1d9a27669a8d301c72165f3249343b834e8' 
  AND token = 'LGd31+wPUbw+wfyNfXXy6uvzo5IfYSAAB6VJhNHrtYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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