SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04c698abc01c665e1d138be9278e41c397119f5057b2847c38d15e36d95f3207' 
  AND token = '6EsNOi33ZMa0XKETLYz5SMFcMeLOCtzkZXiAk5W1f5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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