SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f259f4358b6c3e762c65fa2bebc85c1cc7fa551046bda0047c4a166a2ffea8c' 
  AND token = 'T9Gta8wdHZMdV0Gc6njg8wjF6HzjRGiDj9gix6fARBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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