SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a3a7af4dbc72b3f35066c134dab55096805073e241c26a3950cd8e500a2d7b9' 
  AND token = 'gYNqk5zxLPGgsbYJQVml264iUpdQ3ni5az0WrSK5AwM=' 
  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"
    }
  }
}