SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b90842fde5237c1cf749403a95dfd18ee954b9a2de204d8f5ac318412cf44feb' 
  AND token = 'O/xTzcl/Zv3BqkVWYQnP+zy5jJeXuoFxtyJzMpRkK9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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