SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43d5f9089ff33eb9d615fb9e16ce93b47bf8262272ab458b917f494dbc100827' 
  AND token = '9ebSX5T5Th2QucjFc/vurg2GZlPeaPJoNDRS1zj8p00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}