SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf0598056742119b18695071d1377f7125f23b2e5076e30f3f13b6bfe4e949af' 
  AND token = 'm1HOcbu/zLmNeSVTyRWTw//FeXhBqSNYJso9QcdvWx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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