SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '001d139430fdfa7f983c9501ce34382917fb5936daa16aa0a52b7083143db7b1' 
  AND token = 'O6YjBa4axkpYa0i2w2SzsTezWnqafaCAcWGcWXKsaus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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