SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97c5a82ad77a4d5fc97967da29c518cc99746c9610ec68c86cc24f96ad12cf39' 
  AND token = 'CWdvTomFkAORL0LOwLbGdSYjnloXgPRS7Yjpti07Jsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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