SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '778f0d319dbf4552f01ff468aca8537783a1c543a05aeb37ea536a5c108f6431' 
  AND token = '65jJaULugrOQQF8bqWyHcATHTrL1/LitqGN/0k6+63Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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